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Gus Wheeler FBI Thriller #3
Before the Devil Knows
Sometimes it’s not the devil you know…
When the disfigured body of a missing teenager is found in an unmarked grave in northern Maine, FBI agent Gus Wheeler and his partner arrive to investigate. They discover a second grave, but these remains are so badly burned, identification proves difficult. Yet the two bodies have something strange in a large lead cross laid upon each chest.
The locals are uncooperative, and the rural law enforcement is two steps behind. Enlisting help from a theology and biblical studies expert, they discover the murders are lifted straight from ancient scripture and the burials consistent with an archaic religious practice. Connecting the victims to a specific church adhering to a strict doctrine of the Old Testament creates more confusion than clarity.
As the investigation widens, the agents face threats and suspicion. Then someone inside the church begins leaving them clues, but are they friend or foe? With time running out, Gus must determine if their secret guide is leading them toward the answers or deeper into an underworld of twisted dogma and ancient rituals.
When the disfigured body of a missing teenager is found in an unmarked grave in northern Maine, FBI agent Gus Wheeler and his partner arrive to investigate. They discover a second grave, but these remains are so badly burned, identification proves difficult. Yet the two bodies have something strange in a large lead cross laid upon each chest.
The locals are uncooperative, and the rural law enforcement is two steps behind. Enlisting help from a theology and biblical studies expert, they discover the murders are lifted straight from ancient scripture and the burials consistent with an archaic religious practice. Connecting the victims to a specific church adhering to a strict doctrine of the Old Testament creates more confusion than clarity.
As the investigation widens, the agents face threats and suspicion. Then someone inside the church begins leaving them clues, but are they friend or foe? With time running out, Gus must determine if their secret guide is leading them toward the answers or deeper into an underworld of twisted dogma and ancient rituals.
362 pages, Paperback
Published July 29, 2026
About the author
R. John Dingle
3 books211 followersR. John Dingle lives and writes from a restored 200 year-old house, on a small island in Mid-Coast Maine. The often-haunting themes of the rocky coast, as well as a lifetime of experiences in and around New England’s small towns, farms, and cities, provide excellent inspiration for the tones and moods reflected in Dingle’s mysteries and psychological thrillers. He is the author of the critically acclaimed and multi-award nominated Gus Wheeler FBI Thriller series, which includes Karma Never Sleeps, Wings of Madness, and Before the Devil Knows.
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Displaying 1 - 30 of 163 reviews
June 15, 2026
I. Absolutely. Loved. This. Book. This is the third book on the Gus Wheeler FBI series and I am so invested in them. I am sitting here waiting patiently for the next one. (Hint hint) Gus and V find themselves in Northern Maine investigating unmarked graves buried with lead crosses. It seems to be connected to a religious community but nobody is talking and they don’t like strangers asking questions. Can they find out what’s going on before they end up in the next unmarked graves buried?
July 23, 2026
A teenage body is found in an unmarked grave in northern Maine. Then, a second grave with another body is found that’s been burned badly. Gus and Vanessa do everything they can to get some answers.
But when they begin to look into the town’s folk, they realize these people are highly religious fanatics. No one will cooperate.
Throw in a religious trope to thriller and horror books, and I’m in! It’s one of my favorite tropes. Gus and Vanessa make a great team and the witty back and forth banter was a nice touch.
This is perfect for fans of All The Sinners Bleed by S.A. Cosby! I enjoyed it and look forward to whatever Mr. Dingle comes up with next.
4 ⭐️⭐️⭐️⭐️
Pub Date - 7/29
But when they begin to look into the town’s folk, they realize these people are highly religious fanatics. No one will cooperate.
Throw in a religious trope to thriller and horror books, and I’m in! It’s one of my favorite tropes. Gus and Vanessa make a great team and the witty back and forth banter was a nice touch.
This is perfect for fans of All The Sinners Bleed by S.A. Cosby! I enjoyed it and look forward to whatever Mr. Dingle comes up with next.
4 ⭐️⭐️⭐️⭐️
Pub Date - 7/29
July 30, 2026
This series gets better and better. Before The Devil Knows is book 3 in the series but can definitely be read as a standalone. Gus Wheeler is a fantastic MC and Vanessa is a great partner. This duo is unstoppable and their work relationship is so endearing. I wish I had such amazing colleagues!
I devoured this one. The short chapters were addictive and ended just at the right spot to keep me turning the pages.
This one ends with a nice setup for book 4,and I couldn't be more thrilled!
I devoured this one. The short chapters were addictive and ended just at the right spot to keep me turning the pages.
This one ends with a nice setup for book 4,and I couldn't be more thrilled!
May 23, 2026
Another great read in the Gus Wheeler FBI Series! I’m so excited this series is continuing and I cannot wait to see what unfolds next!
Thank you so much to the author R John Dingle for my gifted arc of Before the Devil Knows. I will read anything he writes it’s just that good!
I absolutely loved the religious tie in with this read. It added so much to the story and was such a unique premise. It was dark , psychological, and its cult like vibe had me questioning everyone and everything.
When a missing teen is found disfigured in an unmarked grave and strange religious practices begin to come to light Agent Gus Wheeler and his team will leave no stone unturned until the case is solved.
Dingle’s writing and his attention to detail sets his crime fiction thrillers apart from the rest. Be sure to add this twisty ride to your summer tbr it releases July 29th!
I cannot wait for book 4 especially with that ending!!
Thank you so much to the author R John Dingle for my gifted arc of Before the Devil Knows. I will read anything he writes it’s just that good!
I absolutely loved the religious tie in with this read. It added so much to the story and was such a unique premise. It was dark , psychological, and its cult like vibe had me questioning everyone and everything.
When a missing teen is found disfigured in an unmarked grave and strange religious practices begin to come to light Agent Gus Wheeler and his team will leave no stone unturned until the case is solved.
Dingle’s writing and his attention to detail sets his crime fiction thrillers apart from the rest. Be sure to add this twisty ride to your summer tbr it releases July 29th!
I cannot wait for book 4 especially with that ending!!
June 20, 2026
I was so excited to start this book - I absolutely LOVED Karma Never Sleeps & Wings of Madness where we meet FBI profiler Gus Wheeler and Vanessa Lambert (I highly recommend reading them!! But please note The Devil Knows can be read as a full standalone!)
I was hooked right from the very first chapter! This is a book that will have you staying up way past your bedtime because you just can’t put it down. This book is fast paced with twists and turns and secrets with just the right amount of creepy feelings sprinkled on top. Gus and Vanessa are quickly becoming two of my favorite characters. Their banter and chemistry is top notch!
No spoilers here - but do yourself a favor and make this your summer thriller read!!
✨What To Expect:
🧠Psychological Thriller
🔪Dark Crime Thriller
👀Old Testament / Cult Vibes
⁉️Suspense & Tension & Mystery
🏡Small Town Maine
🌪️Twists & Turns
🔍Police Procedural
I was hooked right from the very first chapter! This is a book that will have you staying up way past your bedtime because you just can’t put it down. This book is fast paced with twists and turns and secrets with just the right amount of creepy feelings sprinkled on top. Gus and Vanessa are quickly becoming two of my favorite characters. Their banter and chemistry is top notch!
No spoilers here - but do yourself a favor and make this your summer thriller read!!
✨What To Expect:
🧠Psychological Thriller
🔪Dark Crime Thriller
👀Old Testament / Cult Vibes
⁉️Suspense & Tension & Mystery
🏡Small Town Maine
🌪️Twists & Turns
🔍Police Procedural
July 1, 2026
BEFORE THE DEVIL KNOWS by @r.johndingle
📖 book review • out 07.29.26
⭐️⭐️⭐️⭐️
thanks to the author for my box & my signed copy! they all look so good together 😍 @tulepublishing @thrillerbookloversthepulse
book three is by farrrr the darkest book of this series and based on that last page 👀 we may be going even darker the next round. i’m here for it!!!
gus wheeler is back (swipe to see the synopsis on the back of the book) & if you haven’t checked these books out yet, you’re totally missing out. Karma Never Sleeps is one of my favorite thriller debuts, and I love that I’ve had the chance to read every book in the series early! I treasure my copies and hope more people in the world see them, because they’re truly gripping stories (and book 3 will probably have you clutching your pearls) buckle up!!
📖 book review • out 07.29.26
⭐️⭐️⭐️⭐️
thanks to the author for my box & my signed copy! they all look so good together 😍 @tulepublishing @thrillerbookloversthepulse
book three is by farrrr the darkest book of this series and based on that last page 👀 we may be going even darker the next round. i’m here for it!!!
gus wheeler is back (swipe to see the synopsis on the back of the book) & if you haven’t checked these books out yet, you’re totally missing out. Karma Never Sleeps is one of my favorite thriller debuts, and I love that I’ve had the chance to read every book in the series early! I treasure my copies and hope more people in the world see them, because they’re truly gripping stories (and book 3 will probably have you clutching your pearls) buckle up!!
July 31, 2026
Happy Pub Week to this amazing book!
WOW! I loved this one so much! This story truly kept me guessing the entire time and I was blown away by the crazy twists and the ending. I have read previous books by this author and this is definitely my favorite one yet! And that cliffhanger… I already can’t wait for the next book in this series!
Gus and Vanessa make the best FBI investigative duo. They’re both really likeable and so different from each other in the best way. I love how they work together and look out for each other. The generational differences and references also keep me thoroughly entertained!
The rich, vivid descriptions of the very rural small towns in northern Maine made me feel like I was there with the characters. I am also very interested in any and all stories, both fiction and nonfiction, about religious cults - so this topic definitely did not hurt my enjoyment of this one!
I really appreciate the multiple POV, especially when we get a peak into the minds of suspects or side characters who may or may not be involved, with little context. This keeps me on my toes the whole time trying to figure out what the heck is actually happening!
This is definitely a heart pounding, action-packed read that I just could not put down, complete with shocking twists and a jaw dropping ending! I truly thought I had it all figured out. I would NEVER have guessed the big twist at all and I was absolutely shocked when I realized what was actually going on.
This is the third book in the Gus Wheeler FBI Thriller series, and while it does briefly reference the previous books here and there, it can definitely be read as a stand alone. I would highly recommend this one, especially if you enjoy police procedural drama/thrillers and stories about small towns and religious cults!
Thank you to R John Dingle and Tule Publishing for the gifted advanced copy. This is a voluntary and honest review.
WOW! I loved this one so much! This story truly kept me guessing the entire time and I was blown away by the crazy twists and the ending. I have read previous books by this author and this is definitely my favorite one yet! And that cliffhanger… I already can’t wait for the next book in this series!
Gus and Vanessa make the best FBI investigative duo. They’re both really likeable and so different from each other in the best way. I love how they work together and look out for each other. The generational differences and references also keep me thoroughly entertained!
The rich, vivid descriptions of the very rural small towns in northern Maine made me feel like I was there with the characters. I am also very interested in any and all stories, both fiction and nonfiction, about religious cults - so this topic definitely did not hurt my enjoyment of this one!
I really appreciate the multiple POV, especially when we get a peak into the minds of suspects or side characters who may or may not be involved, with little context. This keeps me on my toes the whole time trying to figure out what the heck is actually happening!
This is definitely a heart pounding, action-packed read that I just could not put down, complete with shocking twists and a jaw dropping ending! I truly thought I had it all figured out. I would NEVER have guessed the big twist at all and I was absolutely shocked when I realized what was actually going on.
This is the third book in the Gus Wheeler FBI Thriller series, and while it does briefly reference the previous books here and there, it can definitely be read as a stand alone. I would highly recommend this one, especially if you enjoy police procedural drama/thrillers and stories about small towns and religious cults!
Thank you to R John Dingle and Tule Publishing for the gifted advanced copy. This is a voluntary and honest review.
June 17, 2026
When the body of a missing teenager is discovered in an unmarked grave in northern Maine, FBI agent Gus Wheeler and his partner are called in to investigate. What starts as a murder case quickly becomes more disturbing when a second grave is found and both victims are discovered with large lead crosses placed on their chests. As Gus digs deeper with the help of a theology expert, the investigation leads to a secretive church, ancient religious practices, and a mysterious insider leaving clues. With threats mounting and trust in short supply, Gus must figure out who is helping him before the case pulls him further into a world of twisted beliefs and deadly rituals.
This was an amazing read and my first book by this author, even though it is the third in the Gus Wheeler series. I usually do not read religious themes in my book, but I loved it in this book! The religious elements here were fascinating and added so much to the story, creating a truly unique plot. The dark, psychological atmosphere and cult like vibes had me questioning everyone and everything. The secluded Maine setting made it even more eerie too. The story was fast paced, twisty, and impossible to put down- I finished it in 2 sittings. Also, that ending left me wanting book 4 ASAP and also ready to go back and read the first two books.
Thank you Thriller Book Lovers: The Pulse and the author R. John Dingle for the gifted copy! This book is out July 29, 2026!
This was an amazing read and my first book by this author, even though it is the third in the Gus Wheeler series. I usually do not read religious themes in my book, but I loved it in this book! The religious elements here were fascinating and added so much to the story, creating a truly unique plot. The dark, psychological atmosphere and cult like vibes had me questioning everyone and everything. The secluded Maine setting made it even more eerie too. The story was fast paced, twisty, and impossible to put down- I finished it in 2 sittings. Also, that ending left me wanting book 4 ASAP and also ready to go back and read the first two books.
Thank you Thriller Book Lovers: The Pulse and the author R. John Dingle for the gifted copy! This book is out July 29, 2026!
This entire review has been hidden because of spoilers.
July 27, 2026
Another great installment in the Gus Wheeler series! 🙌
I absolutely love the Gus and Vanessa characters and their dynamic! I was sucked in immediately and couldn’t turn the pages fast enough! While this is the third book in the series, it can be read as a standalone. But I recommend starting with the first book because this series is just that good!! 👏
Thank you R. John Dingle for the opportunity to read the eARC in exchange for my honest review! ❤️
I absolutely love the Gus and Vanessa characters and their dynamic! I was sucked in immediately and couldn’t turn the pages fast enough! While this is the third book in the series, it can be read as a standalone. But I recommend starting with the first book because this series is just that good!! 👏
Thank you R. John Dingle for the opportunity to read the eARC in exchange for my honest review! ❤️
July 9, 2026
the fact that the first chapter had me already saying wtf at the end, i immediately knew this was going to be a good one.
this was my first book by this author, & he did not disappoint! i was hooked pretty much from the start. the eerie atmosphere in the small town, where there seems to be eyes everywhere, kept me fully invested! it made me put in my detective hat on, trying to figure everything out before the characters did. i got a couple of twists, but that one near the end? i did not see coming! (can’t get them all, lol)
gus & vanessa made a great team. i loved their friendship & the banter between them both. she had me laughing more than once. “skip intro” 😂
overall, i definitely enjoyed this one. i loved trying to piece everything together, & the ending has me dying to know what happens next! although this is the 3rd book in the series, it can easily be read as a standalone.
𝐫𝐞𝐚𝐝 𝐢𝐟 𝐲𝐨𝐮 𝐥𝐨𝐯𝐞:
♡ fbi investigation
♡ detective thriller
♡ religious retribution
♡ murders/disappearances
♡ suspenseful & twisty
♡ small town
♡ fast paced
♡ short chapters
thank you r. john dingle for the advance copy in exchange for an honest review.
this was my first book by this author, & he did not disappoint! i was hooked pretty much from the start. the eerie atmosphere in the small town, where there seems to be eyes everywhere, kept me fully invested! it made me put in my detective hat on, trying to figure everything out before the characters did. i got a couple of twists, but that one near the end? i did not see coming! (can’t get them all, lol)
gus & vanessa made a great team. i loved their friendship & the banter between them both. she had me laughing more than once. “skip intro” 😂
overall, i definitely enjoyed this one. i loved trying to piece everything together, & the ending has me dying to know what happens next! although this is the 3rd book in the series, it can easily be read as a standalone.
𝐫𝐞𝐚𝐝 𝐢𝐟 𝐲𝐨𝐮 𝐥𝐨𝐯𝐞:
♡ fbi investigation
♡ detective thriller
♡ religious retribution
♡ murders/disappearances
♡ suspenseful & twisty
♡ small town
♡ fast paced
♡ short chapters
thank you r. john dingle for the advance copy in exchange for an honest review.
July 30, 2026
Book Review
Before The Devil Knows
A Novel Written By R. John Dingle
Fiction - Thriller
Published July 2026
403 Pages
⭐️⭐️⭐️⭐️⭐️
This is the third book in the author’s Gus Wheeler FBI Thriller Series. This book was full of mystery and suspense. I love going along with Gus and his partner, Vanessa Lambert, as they solve crimes. This book took them to the isolated area of northern Maine.
Gus and Vanessa have been sent to Maine to investigate the murder of a teenage boy. The murder has religious overtones. The boy’s murder has led to the discovery of more bodies in unmarked graves.
As the two detectives investigate their lives have been put in danger. Were the murders committed by members of a fanatical religious cult? Were they the result of some type of vigilante justice?
This story is full of suspense. The twists just keep coming. The only characters to trust are Gus and Vanessa. The ending - Wow! I can’t wait for book four!
“This is feelin’ a lot less Norman Rockwell and a lot more Stephen King.”
Before The Devil Knows
A Novel Written By R. John Dingle
Fiction - Thriller
Published July 2026
403 Pages
⭐️⭐️⭐️⭐️⭐️
This is the third book in the author’s Gus Wheeler FBI Thriller Series. This book was full of mystery and suspense. I love going along with Gus and his partner, Vanessa Lambert, as they solve crimes. This book took them to the isolated area of northern Maine.
Gus and Vanessa have been sent to Maine to investigate the murder of a teenage boy. The murder has religious overtones. The boy’s murder has led to the discovery of more bodies in unmarked graves.
As the two detectives investigate their lives have been put in danger. Were the murders committed by members of a fanatical religious cult? Were they the result of some type of vigilante justice?
This story is full of suspense. The twists just keep coming. The only characters to trust are Gus and Vanessa. The ending - Wow! I can’t wait for book four!
“This is feelin’ a lot less Norman Rockwell and a lot more Stephen King.”
July 30, 2026
"For now was not the time to contemplate the evil that existed in this life. Now was the time for Gus to find the evil that existed from the next."
FBI Agent Gus Wheeler is back with another mysterious investigation in Northern Maine. When a local teen goes missing, the search uncovers a dark secret hidden within the walls of a local church.
I haven't read many thrillers, but when I see @r.johndingle has a new book releasing, I know I am in for a ride and I have to read it!! I love this interconnected series and how it ties in with the characters who I enjoy reading about.
The story plot is so unique with the religion woven into this thriller series. I love all the twists this story has and I just enjoy when a moment catches me gasping. I am always caught by surprise and I loved every moment of that!
Such a fun and entertaining read that is easy and definitely kept me up late at night as I couldn't stop reading! Congratulations @r.johndingle for another amazing Gus Wheeler release!! Thank you for letting me tag along on this fun adventure!
FBI Agent Gus Wheeler is back with another mysterious investigation in Northern Maine. When a local teen goes missing, the search uncovers a dark secret hidden within the walls of a local church.
I haven't read many thrillers, but when I see @r.johndingle has a new book releasing, I know I am in for a ride and I have to read it!! I love this interconnected series and how it ties in with the characters who I enjoy reading about.
The story plot is so unique with the religion woven into this thriller series. I love all the twists this story has and I just enjoy when a moment catches me gasping. I am always caught by surprise and I loved every moment of that!
Such a fun and entertaining read that is easy and definitely kept me up late at night as I couldn't stop reading! Congratulations @r.johndingle for another amazing Gus Wheeler release!! Thank you for letting me tag along on this fun adventure!
July 2, 2026
⭐️⭐️⭐️⭐️⭐️
Book number 3 of the Gus Wheeler series (however can be read as a standalone and this was the first book I have read in the series). I had the opportunity to read this complimentary in exchange for an honest review and it did not disappoint! It’s a great read for those that are into fbi or detective thrillers, it had me on the edge of my seat until the very end. The two fbi agents, Gus and V, complement each other with their different personalities. The story is set in very rural northern Maine which adds an additional set of challenges for the agents to solve this complex and multi layered case. Lastly, this book was very fast paced and made it quite difficult to put down which is essential in this genre.
Book number 3 of the Gus Wheeler series (however can be read as a standalone and this was the first book I have read in the series). I had the opportunity to read this complimentary in exchange for an honest review and it did not disappoint! It’s a great read for those that are into fbi or detective thrillers, it had me on the edge of my seat until the very end. The two fbi agents, Gus and V, complement each other with their different personalities. The story is set in very rural northern Maine which adds an additional set of challenges for the agents to solve this complex and multi layered case. Lastly, this book was very fast paced and made it quite difficult to put down which is essential in this genre.
June 21, 2026
Book Title: Before the Devil Knows (Gus Wheeler FBI Thriller Book 3)
Author: R. John Dingle
Publisher: Tule Publishing
Pub Date: July 29, 2026
Dates Read/Listened: April 14, 2026 – May 9, 2026
🗣️ 𝚀𝚞𝚒𝚌𝚔(𝚒𝚜𝚑) 𝚃𝚊𝚔𝚎: R. John Dingle has really outdone himself this time, and it is my personal opinion that Before the Devil Knows is now the best book in the Gus Wheeler series. This one really hit for me, and the religious aspect of the deaths made it feel even more ominous. The small-town vibes abound, and no one is quick (or willing) to help Gus and Vanessa find the killer. Or killers…? 🤔 It was such a creepy and action-packed ride that never lets up. The conclusion was positively wild, and it was the perfect way to wrap up this FBI thriller. I love Gus and V so much, and they are such easy characters to root for, so it’s always hard when you see anything bad happen to them, though you know that’s basically going to be a given. I was definitely left wanting more, and I can’t wait to see where the next book takes us! PSA: Not for the faint of heart. 😉
T͏h͏i͏s͏ B͏o͏o͏k͏ i͏n͏ 5͏ E͏m͏o͏j͏i͏’s͏ o͏r͏ L͏e͏s͏s͏: 🪦✝️🚓🎶
𝙱𝚘𝚘𝚔 𝚁𝚊𝚝𝚒𝚗𝚐: 🌟🌟🌟🌟🌟
I received a complimentary copy of this book. Opinions expressed in this review are completely my own.
Author: R. John Dingle
Publisher: Tule Publishing
Pub Date: July 29, 2026
Dates Read/Listened: April 14, 2026 – May 9, 2026
🗣️ 𝚀𝚞𝚒𝚌𝚔(𝚒𝚜𝚑) 𝚃𝚊𝚔𝚎: R. John Dingle has really outdone himself this time, and it is my personal opinion that Before the Devil Knows is now the best book in the Gus Wheeler series. This one really hit for me, and the religious aspect of the deaths made it feel even more ominous. The small-town vibes abound, and no one is quick (or willing) to help Gus and Vanessa find the killer. Or killers…? 🤔 It was such a creepy and action-packed ride that never lets up. The conclusion was positively wild, and it was the perfect way to wrap up this FBI thriller. I love Gus and V so much, and they are such easy characters to root for, so it’s always hard when you see anything bad happen to them, though you know that’s basically going to be a given. I was definitely left wanting more, and I can’t wait to see where the next book takes us! PSA: Not for the faint of heart. 😉
T͏h͏i͏s͏ B͏o͏o͏k͏ i͏n͏ 5͏ E͏m͏o͏j͏i͏’s͏ o͏r͏ L͏e͏s͏s͏: 🪦✝️🚓🎶
𝙱𝚘𝚘𝚔 𝚁𝚊𝚝𝚒𝚗𝚐: 🌟🌟🌟🌟🌟
I received a complimentary copy of this book. Opinions expressed in this review are completely my own.
July 29, 2026
In far northern Maine, FBI agents Gus Wheeler and Vanessa Lambert are called upon to investigate the murder of a teenaged boy. What they discover leads them to realize that there’s a serial killer, or killers, running unchecked in the remote and rural area. As the agents dig further, they discover kidnappings, ritual murders, religious extremism, and cover-ups that appear to originate with a cultish church. When they’re approached by a young woman offering inside information about what goes on in the church, they’re concerned but eager to use that information in hope of finding the perpetrator behind the killings.
The local people are unhappy with the agents’ presence. It’s a community that believes in dealing with everything on their own, and that includes doling out justice and punishment. Agents Wheeler and Lambert find their lives endangered on more than one occasion. Ingenuity and resourcefulness, not to mention dedication and a healthy dose of luck, keep the agents alive and more determined than ever to find who is behind what’s happening.
This was the first book by R. John Dingle that I’ve read. It will not be the last. I was pleasantly surprised by how well-written and engaging the story was. While I figured out a part of who was behind the murders, the story still kept me guessing up until the end to see if I was right, and if there was more involved than I thought. There was.
This is book three in the Gus Wheeler FBI Thriller series, but obviously, it was the first I’ve read. It worked perfectly as a standalone. I enjoyed it very much, and it won’t be the last book of his that I read. I highly recommend it.
I received an advanced reader copy of this book from the publisher, Tule. I thank all involved for their generosity in sharing this book with me, but it had no effect on this review. All opinions in this review reflect my true and honest reactions to reading this book.
The local people are unhappy with the agents’ presence. It’s a community that believes in dealing with everything on their own, and that includes doling out justice and punishment. Agents Wheeler and Lambert find their lives endangered on more than one occasion. Ingenuity and resourcefulness, not to mention dedication and a healthy dose of luck, keep the agents alive and more determined than ever to find who is behind what’s happening.
This was the first book by R. John Dingle that I’ve read. It will not be the last. I was pleasantly surprised by how well-written and engaging the story was. While I figured out a part of who was behind the murders, the story still kept me guessing up until the end to see if I was right, and if there was more involved than I thought. There was.
This is book three in the Gus Wheeler FBI Thriller series, but obviously, it was the first I’ve read. It worked perfectly as a standalone. I enjoyed it very much, and it won’t be the last book of his that I read. I highly recommend it.
I received an advanced reader copy of this book from the publisher, Tule. I thank all involved for their generosity in sharing this book with me, but it had no effect on this review. All opinions in this review reflect my true and honest reactions to reading this book.
June 25, 2026
Mr. Dingle, can I just say... your books keep getting better and better!
This series has everything I love: fast pacing, short chapters with those mini cliffhangers (”just one more chapter” vibes), dark psychological depth, unsettling trauma, and twists that keep coming.
In Before The Devil Knows, the focus is on religious fanaticism, which gives this one an especially eerie edge. I find the psychology behind it fascinating, while also feeling genuinely unsettled by what people were willing to do in the name of faith.
And Gus and Vanessa? They just keep getting stronger as a duo. By now, they feel like old friends. We know what makes them tick, we understand their humor, and their partnership feels authentic and earned. I love experiencing the investigations through their perspectives—their intelligence, instincts, and observations make every case feel like I'm part of the duo. And honestly, Gus's brain full of racing monkeys makes me feel very seen. 😂
Dingle, I’m a forever fan!!! Dingle writes clever detective stories packed with memorable details. I loved Vanessa's "final girl" references, the The Shining nods, and I swear I spotted the previous two titles in the story - a little play on words maybe???
Needless to say, I'm already impatiently waiting for Book 4.
Final Verdict: 👍 100% yes! An excellent crime novel that blends forensic investigation, psychological suspense, and religious fanaticism into a gripping mystery. Plus, Gus and Vanessa are investigators you'll absolutely want to spend more time with.
This series has everything I love: fast pacing, short chapters with those mini cliffhangers (”just one more chapter” vibes), dark psychological depth, unsettling trauma, and twists that keep coming.
In Before The Devil Knows, the focus is on religious fanaticism, which gives this one an especially eerie edge. I find the psychology behind it fascinating, while also feeling genuinely unsettled by what people were willing to do in the name of faith.
And Gus and Vanessa? They just keep getting stronger as a duo. By now, they feel like old friends. We know what makes them tick, we understand their humor, and their partnership feels authentic and earned. I love experiencing the investigations through their perspectives—their intelligence, instincts, and observations make every case feel like I'm part of the duo. And honestly, Gus's brain full of racing monkeys makes me feel very seen. 😂
Dingle, I’m a forever fan!!! Dingle writes clever detective stories packed with memorable details. I loved Vanessa's "final girl" references, the The Shining nods, and I swear I spotted the previous two titles in the story - a little play on words maybe???
Needless to say, I'm already impatiently waiting for Book 4.
Final Verdict: 👍 100% yes! An excellent crime novel that blends forensic investigation, psychological suspense, and religious fanaticism into a gripping mystery. Plus, Gus and Vanessa are investigators you'll absolutely want to spend more time with.
June 30, 2026
Genre: Thriller
FBI Thriller
🩸 Murder
🪦 Unmarked Grave
⛪️ God’s Will
👮🏼 Religious Clues
❓ Who is behind it
My Take - Speechless! Wow! Book 3 hit hard. The emotions, suspense, twists, and turns. The uncertainty. I was on a roller coaster. I did not know how to feel. I was on edge with every chapter I turned the page to. I love Gus and Vanessa! They are not just partners. They have such a special friendship and bond. Together they are a dynamic duo. In this third book you can really tell their character growth and see their personalities come out. The narrator in this book had me a little twisted. Like what is going on here. The diaolgue between characters was top notch and enaging. I felt like I was deep in this investigation with Gus and Vanessa.
Quick Summary -
Gus and Vanessa are at it again in a small town of northern Maine. Called into investigate a body found in an unmarked grave. This investigation had challenges right from the start. But in Gus and Vanessa fashion they were determined to get to the bottom of it. Gus and Vanessa noticed religious clues right away at the site of the unmarked grave. They knew they were in a little over their head. Therefore, they called in a religious expert to help the decipher the clues. Is the church and their members really responsible?
FBI Thriller
🩸 Murder
🪦 Unmarked Grave
⛪️ God’s Will
👮🏼 Religious Clues
❓ Who is behind it
My Take - Speechless! Wow! Book 3 hit hard. The emotions, suspense, twists, and turns. The uncertainty. I was on a roller coaster. I did not know how to feel. I was on edge with every chapter I turned the page to. I love Gus and Vanessa! They are not just partners. They have such a special friendship and bond. Together they are a dynamic duo. In this third book you can really tell their character growth and see their personalities come out. The narrator in this book had me a little twisted. Like what is going on here. The diaolgue between characters was top notch and enaging. I felt like I was deep in this investigation with Gus and Vanessa.
Quick Summary -
Gus and Vanessa are at it again in a small town of northern Maine. Called into investigate a body found in an unmarked grave. This investigation had challenges right from the start. But in Gus and Vanessa fashion they were determined to get to the bottom of it. Gus and Vanessa noticed religious clues right away at the site of the unmarked grave. They knew they were in a little over their head. Therefore, they called in a religious expert to help the decipher the clues. Is the church and their members really responsible?
June 5, 2026
⭐⭐⭐⭐/5
📚 Before the Devil Knows by R. John Dingle 📚
This is my third ARC from R. John Dingle, and at this point, I’ll pretty much read anything he writes! 🙌
What really hooked me with this one was the cult aspect. 👀 I always love a good cult storyline, and this book delivered plenty of mystery, suspense, and twists to keep the pages turning. The writing style is so smooth and accessible that I flew through it without ever feeling bogged down.
I also loved that the story takes place in Maine. 🦞🌲 Being from New England, it made the setting feel even more immersive and familiar. Another highlight was the partnership between Gus and V. Their dynamic continues to be one of my favorite parts of this series, and I loved spending more time with them.
The Gen Z lingo sprinkled throughout the book gave it a modern feel and even had me laughing a few times. 😆
Most importantly, I’m so excited that this series is continuing! 🎉 There are definitely more adventures ahead for Gus and V, and I’ll be first in line to read them.
If you’re a fan of fast-paced mysteries, cult-centered storylines, memorable characters, and easy-to-devour writing, this series is absolutely worth checking out. 📖✨
Thank you to the author and publisher for the ARC in exchange for an honest review.
📚 Before the Devil Knows by R. John Dingle 📚
This is my third ARC from R. John Dingle, and at this point, I’ll pretty much read anything he writes! 🙌
What really hooked me with this one was the cult aspect. 👀 I always love a good cult storyline, and this book delivered plenty of mystery, suspense, and twists to keep the pages turning. The writing style is so smooth and accessible that I flew through it without ever feeling bogged down.
I also loved that the story takes place in Maine. 🦞🌲 Being from New England, it made the setting feel even more immersive and familiar. Another highlight was the partnership between Gus and V. Their dynamic continues to be one of my favorite parts of this series, and I loved spending more time with them.
The Gen Z lingo sprinkled throughout the book gave it a modern feel and even had me laughing a few times. 😆
Most importantly, I’m so excited that this series is continuing! 🎉 There are definitely more adventures ahead for Gus and V, and I’ll be first in line to read them.
If you’re a fan of fast-paced mysteries, cult-centered storylines, memorable characters, and easy-to-devour writing, this series is absolutely worth checking out. 📖✨
Thank you to the author and publisher for the ARC in exchange for an honest review.
June 9, 2026
I’ll be honest, was skeptical going into this one based on the title. Horror isn’t really my thing, and I typically stay away from books that heavily involve the devil or demonic themes. But I’m so glad I gave this book a chance because it completely won me over.
At its core, this is an investigative thriller, and that is exactly where it shines. When the body of a teenager is discovered, it sets off a chain of clues leading to another set of remains… and then another… and another. What starts as a single case quickly evolves into something much bigger, and I was hooked from the very beginning.
One of my favorite parts of the book was the dynamic between Gus and V. Their partnership felt natural, and I loved following them as they unraveled the mystery piece by piece. The investigation was compelling, the clues were intriguing, and the pacing kept me fully invested.
This book kept me engaged from page one, and I found myself constantly wanting to read just one more chapter. Before I knew it, I was completely immersed in the story.
Now I feel like I need to go back and read the first two Gus Wheeler Thrillers because if they’re anything like this one, I’m all in. A gripping, well-paced thriller that exceeded my expectations in every way.
At its core, this is an investigative thriller, and that is exactly where it shines. When the body of a teenager is discovered, it sets off a chain of clues leading to another set of remains… and then another… and another. What starts as a single case quickly evolves into something much bigger, and I was hooked from the very beginning.
One of my favorite parts of the book was the dynamic between Gus and V. Their partnership felt natural, and I loved following them as they unraveled the mystery piece by piece. The investigation was compelling, the clues were intriguing, and the pacing kept me fully invested.
This book kept me engaged from page one, and I found myself constantly wanting to read just one more chapter. Before I knew it, I was completely immersed in the story.
Now I feel like I need to go back and read the first two Gus Wheeler Thrillers because if they’re anything like this one, I’m all in. A gripping, well-paced thriller that exceeded my expectations in every way.
July 1, 2026
I was super excited to be able to receive an arc of this book! The last one was great and this one is no different. Really great book and series in all. R. John Dingle became my auto read author. And soon my autobuy author I just need to set up my library so I can display them! I’m a big fan of fbi series whether it’s a tv show or book. But by far John is my favorite and to go to for an fbi thrill. What I really enjoy about the way he writes the book and the characters is that you get to follow Gus and Vanessa solving the crime. Looking for clues and investigating who the killer is. And their reasoning behind it. Love to see their thought process. In this book it dealt with religious beliefs and a sort of cult type of vibe. And if you’ve seen those episodes with religion and cults you already know the vibe it’s going to give. It gets crazy when Gus starts to discover bodies with unknown identities. You read that right. Bodiessssss not one, two or three but many. Again such a great chase, very interesting, fast paced and it catches your attention. Absolutely love Gus and Vanessa. I can’t wait to continue the next book in this series. Hope to see more of Gus.
Would I recommend?
Yes!
Would I recommend?
Yes!
July 2, 2026
This series just keeps getting better with every book, and this third installment is my favorite yet! I was hooked from the very first page and genuinely could not put it down. The pacing was perfect, with twists that kept me guessing and just enough suspense to make it impossible to stop reading.
One of my favorite things about this series is the characters. They continue to grow with each book, and I’ve become so invested in them that it feels like catching up with old friends—if those friends constantly found themselves in the middle of heart-pounding mysteries.
The author’s writing style is incredibly engaging, making every chapter fly by while building tension at just the right pace. I was fortunate enough to read an advance copy, and it exceeded every expectation I had.
If you’ve loved the first two books, you’re going to be blown away by this one. And if you haven’t started the series yet, now is the perfect time—because this third book proves the series only gets stronger. I can’t wait to see what comes next!
*I received a complimentary advance copy in exchange for a review.
One of my favorite things about this series is the characters. They continue to grow with each book, and I’ve become so invested in them that it feels like catching up with old friends—if those friends constantly found themselves in the middle of heart-pounding mysteries.
The author’s writing style is incredibly engaging, making every chapter fly by while building tension at just the right pace. I was fortunate enough to read an advance copy, and it exceeded every expectation I had.
If you’ve loved the first two books, you’re going to be blown away by this one. And if you haven’t started the series yet, now is the perfect time—because this third book proves the series only gets stronger. I can’t wait to see what comes next!
*I received a complimentary advance copy in exchange for a review.
June 4, 2026
I had the honor and privilege of reading an ARC of this high anticipated release and (no surprise here) it did not disappoint!
@r.johndingle has crafted yet another addicting mystery centered around our favorite FBI duo, Gus and Vanessa. The stakes were high, the twists were twisting and I couldn’t put this book down.
I absolutely love the dynamic between these two characters - the witty banter and fierce loyalty that’s been built and has grown since book one is so fun to read. The best part is how, once again, this can absolutely be read as a standalone BUT do yourself a favor and read them all.
It’s evident that the author really did his homework for this story - I won’t say much more because I fear I’ll ramble and give things away 😅 but I will say that I 100% recommend you add this to your summer TBR.
Now that the trifecta is complete…I can only hope book four is in the works 😳
Before the Devil Knows is making its way to a bookstore near you on July 29th 🗓️
@r.johndingle has crafted yet another addicting mystery centered around our favorite FBI duo, Gus and Vanessa. The stakes were high, the twists were twisting and I couldn’t put this book down.
I absolutely love the dynamic between these two characters - the witty banter and fierce loyalty that’s been built and has grown since book one is so fun to read. The best part is how, once again, this can absolutely be read as a standalone BUT do yourself a favor and read them all.
It’s evident that the author really did his homework for this story - I won’t say much more because I fear I’ll ramble and give things away 😅 but I will say that I 100% recommend you add this to your summer TBR.
Now that the trifecta is complete…I can only hope book four is in the works 😳
Before the Devil Knows is making its way to a bookstore near you on July 29th 🗓️
June 10, 2026
Gus and V are back and their new case takes them to rural Maine where they have to solve a string of Old Testament style murders.
This book was SO good! Such an easy 5 stars! And I swear this series gets better and better each book! This was such an interesting case and you get totally drawn into the story in the first chapter! The quick, intense chapters keep you totally absorbed in the story and I could not put this down! And the Old Testament/religious zealots themes made the story so intense! And the ending has me so excited for the next book!
If you enjoy a fast paced FBI thriller then I highly recommend picking this series up!
While this book can technically be read as a standalone there are references to the previous two books so I’d recommend reading them first! They’re definitely worth the read!
This book was SO good! Such an easy 5 stars! And I swear this series gets better and better each book! This was such an interesting case and you get totally drawn into the story in the first chapter! The quick, intense chapters keep you totally absorbed in the story and I could not put this down! And the Old Testament/religious zealots themes made the story so intense! And the ending has me so excited for the next book!
If you enjoy a fast paced FBI thriller then I highly recommend picking this series up!
While this book can technically be read as a standalone there are references to the previous two books so I’d recommend reading them first! They’re definitely worth the read!
Review of advance copy received from Author
After reading the first two Gus Wheeler books, I was thrilled to read Before the Devil Knows. It did not disappoint! Set in a small Maine town, Gus and his partner Vanessa are investigating a series of murders. As the victims are discovered, they find that the causes of death are unusual and suggest that the killer was motivated by strict Old Testament religious beliefs. The victims were punished for their perceived sins. To point him in the right direction, Gus consults an expert in religious theology. Together, they try to interpret the strange causes of death and the significance of objects left at the graves. Gus and Vanessa try to untangle the truth before they become the next victims.
The religious elements definitely give this story a spooky feel, almost like an eerie campfire tale. The ending is a bit of a cliffhanger and I can’t wait to read the next one!
The religious elements definitely give this story a spooky feel, almost like an eerie campfire tale. The ending is a bit of a cliffhanger and I can’t wait to read the next one!
May 31, 2026
Thanks to Bookstagrammer Bone Chilling Books for my ARC. I love the Gus Wheeler series, and after reading the first book back in January, I was excited to get my hands on the newest release!
This is by far the best book in the series so far. It delivers nonstop action and suspense from beginning to end. I finished it in a single weekend because I simply couldn’t put it down.
Just when I thought I had everything figured out, the story took a twist I never saw coming. The author never disappoints, and this book kept me guessing until the very end. Reading this book gave me serious Criminal Minds vibes, which made it even more enjoyable.
I am already ready for the next book and can’t wait to see what happens next in the Gus Wheeler series!
Rating: ⭐⭐⭐⭐⭐
This is by far the best book in the series so far. It delivers nonstop action and suspense from beginning to end. I finished it in a single weekend because I simply couldn’t put it down.
Just when I thought I had everything figured out, the story took a twist I never saw coming. The author never disappoints, and this book kept me guessing until the very end. Reading this book gave me serious Criminal Minds vibes, which made it even more enjoyable.
I am already ready for the next book and can’t wait to see what happens next in the Gus Wheeler series!
Rating: ⭐⭐⭐⭐⭐
July 2, 2026
My fellow Thriller Book Lovers The Pulse members and I really enjoyed this new Gus Wheeler story, book 3 in the Gus Wheeler FBI series. With its short chapters, many good twists, and tense action scenes, this one pulled me in.
I liked the small town rural Maine setting and the religious cult storyline. The members of the cult were really quite creepy. Gus and Vanessa’s (his colleague) sibling-like relationship continued to evolve which was nice to see.
I liked seeing how the murder investigation unfolded and how the various elements came together in an exciting ending and a great set-up for book 4.
I recommend this really well-done series!
Thanks to the publisher for the complimentary digital copy. All opinions are my own.
I liked the small town rural Maine setting and the religious cult storyline. The members of the cult were really quite creepy. Gus and Vanessa’s (his colleague) sibling-like relationship continued to evolve which was nice to see.
I liked seeing how the murder investigation unfolded and how the various elements came together in an exciting ending and a great set-up for book 4.
I recommend this really well-done series!
Thanks to the publisher for the complimentary digital copy. All opinions are my own.
April 17, 2026
Gus and Vanessa are back at it again. I love the dynamic of their partnership and I love reading about their cases. They always seem to find themselves in danger but it’s all part of the job. This book had its hooks in me from the very beginning. It was like watching a movie on screen and I couldn’t look away. It was action-packed and fast-paced. I felt like I was trying to solve the case right along with them. Just when you think you know how things are going to end, there’s a twist that throws you for a loop. I loved every second of it and can’t wait to devour the next book!
July 8, 2026
Wow! That is all I need to say about Gus Wheeler’s 3rd book in this FBI series. Gus and his partner, Vanessa, are called to northern Maine to solve deaths of a mysterious nature that appear to be related to religion. Think The DaVinci Code but without the multiple country trip.
I would recommend reading all the books in the series in order to get the full effect of Gus and Vanessa and how their partnership has evolved. Gus is serious and Vanessa is funny and both do their jobs very well.
I am in love with this series and already can’t wait for the next book.
I would recommend reading all the books in the series in order to get the full effect of Gus and Vanessa and how their partnership has evolved. Gus is serious and Vanessa is funny and both do their jobs very well.
I am in love with this series and already can’t wait for the next book.
July 29, 2026
Before the Devil Knows (Gus Wheeler FBI Thriller Book 3) by R. John Dingle is a thrilling FBI murder mystery. A town of religious extremists that have little to do with God and a lot to do with perverted teaching make this a chilling and a bit creepy of a tale. Bodies found in unmarked graves in Northern Maine set Gus and Vanessa off to stop and catch a killer. One story that will have you reading long after bedtime but also wanting to keep the lights on while you do. A fine FBI thriller that make these the two you want on the case.
July 30, 2026
Gus and V are amazing at what they do. Mind you, they do get lucky occasionally, and them both being alive is a bit of a miracle, BUT they are good stay what they do.
As for this book, you will NEVER see the ending coming. I swear I sat here all high and might thinking I knew, but I DIDN'T.
It's a guessing game from beginning to end, with lots of crazy in the middle.
Sit down and buckle up, you won't want to get off this ride!!!
As for this book, you will NEVER see the ending coming. I swear I sat here all high and might thinking I knew, but I DIDN'T.
It's a guessing game from beginning to end, with lots of crazy in the middle.
Sit down and buckle up, you won't want to get off this ride!!!
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