What do you think?
The Nature of Monsters: A Sadie Gray FBI Mystery Series
USA TODAY BESTSELLING AUTHOR, AMAZON ALL-STAR AWARD WINNER, AND #1 BESTSELLING MYSTERY AUTHOR
"I love this series! I’m in love with Sadie and Brad! This series keeps you moving through all the feels! You guys can’t write them fast enough for me!" - B. Bade, Amazon Reviewer
The dark side of law enforcement
Exists only in the shadows.
Sadie’s time has come…
Are you ready?
With Brad away at Quantico for his final interview with the BAU, Sadie is brought into a task force set up by DEA Agent Luke Calloway, and three other shadowy figures. This black-project mission bears the “Above Top Secret” classification and will test every fiber of Sadie’s being.
A woman wakes up in an LA dumpster to find the last 24 hours of her life erased with no memory of what happened. She is not alone. A wave of similar crimes is unfolding in the LA area with no explanation. Worse, each victim has been violated with no memory of the event, only the evidence left behind.
This is not fentanyl, rohypnol, or even tainted cocaine… this is far worse. So bad, in fact, that the powers that be are letting this off-the-books task force operate without rules or oversight, only a prescribed find who’s doing this and stop them.
Permanently.
Sadie is about to go as dark and as deep as she’s ever been undercover, into a world few will ever see, on a case where going too far is what’s required when faced with the nature of monsters.
What will become of Sadie Gray, Brad Tulle, and everything they built? They say the road to Hell is paved with good intentions.
Sadie has plenty. And Hell awaits…
"I love this series! I’m in love with Sadie and Brad! This series keeps you moving through all the feels! You guys can’t write them fast enough for me!" - B. Bade, Amazon Reviewer
The dark side of law enforcement
Exists only in the shadows.
Sadie’s time has come…
Are you ready?
With Brad away at Quantico for his final interview with the BAU, Sadie is brought into a task force set up by DEA Agent Luke Calloway, and three other shadowy figures. This black-project mission bears the “Above Top Secret” classification and will test every fiber of Sadie’s being.
A woman wakes up in an LA dumpster to find the last 24 hours of her life erased with no memory of what happened. She is not alone. A wave of similar crimes is unfolding in the LA area with no explanation. Worse, each victim has been violated with no memory of the event, only the evidence left behind.
This is not fentanyl, rohypnol, or even tainted cocaine… this is far worse. So bad, in fact, that the powers that be are letting this off-the-books task force operate without rules or oversight, only a prescribed find who’s doing this and stop them.
Permanently.
Sadie is about to go as dark and as deep as she’s ever been undercover, into a world few will ever see, on a case where going too far is what’s required when faced with the nature of monsters.
What will become of Sadie Gray, Brad Tulle, and everything they built? They say the road to Hell is paved with good intentions.
Sadie has plenty. And Hell awaits…
271 pages, Kindle Edition
Published June 18, 2026
Ratings & Reviews
Friends & Following
Create a free account to discover what your friends think of this book!
Community Reviews
Displaying 1 - 20 of 20 reviews
June 27, 2026
OMG…just when I thought the Sadie Gray series couldn’t get any better…he’s done it again! I would have finished it sooner if work and sleep didn’t interfere!! So glad Brad picked to say at the FBI…def interested to see what the next step is for them!!!
June 26, 2026
Such a great story
Sadie works for the FBI as an agent that searches out serial killers. She owns her own Julius Cesar, a dog that is not sure who he belongs too. A sister that was kidnapped with her when they were children that was adopted from her. A father in prison for killing said kidnapper, and her mother that left them at a young age from alcohol. I benzed read one after the other until I came to the last two books and took a break. This series Will make you laugh, cry, stay up late to read just one more page. it is worth the read.
Sadie works for the FBI as an agent that searches out serial killers. She owns her own Julius Cesar, a dog that is not sure who he belongs too. A sister that was kidnapped with her when they were children that was adopted from her. A father in prison for killing said kidnapper, and her mother that left them at a young age from alcohol. I benzed read one after the other until I came to the last two books and took a break. This series Will make you laugh, cry, stay up late to read just one more page. it is worth the read.
June 29, 2026
Another great read! Non-stop action!
I was so excited for this newest installment in the Sadie Gray mystery series and it did not disappoint. Finished this read in only one day. Most surprising was the return of familiar characters; Kane, Esty, Codrin, Leopold.... If you're a long time fan I won't spoil the plot, but you can trust that that this adventure with all its twists and turns, does not disappoint!
Strongly recommend this series, looking forward to the next Sadie Gray adventure!
I was so excited for this newest installment in the Sadie Gray mystery series and it did not disappoint. Finished this read in only one day. Most surprising was the return of familiar characters; Kane, Esty, Codrin, Leopold.... If you're a long time fan I won't spoil the plot, but you can trust that that this adventure with all its twists and turns, does not disappoint!
Strongly recommend this series, looking forward to the next Sadie Gray adventure!
September 13, 2026
Wanting more
While super unrealistic, the entire series outlines how I believe the system really is and quite frankly how things may actually become some day. I would absolutely love for this serial continue or a new series to begin. If this is the last, ill be s disappointed. I actually loved it enough to upload and start the last series R B Schulz wrote. I hope it turns out to be as good or, if possible, better.
While super unrealistic, the entire series outlines how I believe the system really is and quite frankly how things may actually become some day. I would absolutely love for this serial continue or a new series to begin. If this is the last, ill be s disappointed. I actually loved it enough to upload and start the last series R B Schulz wrote. I hope it turns out to be as good or, if possible, better.
June 21, 2026
This book was worth the wait!
I have read the entire series and liked each book! I had to wait for this book’s release. It was well worth the wait! This book is my favorite by far. I read it straight through. I couldn’t put it down! This book is so fast paced I feel that I did everything Sadie did! This is a heart pounding book! Loved it!
I have read the entire series and liked each book! I had to wait for this book’s release. It was well worth the wait! This book is my favorite by far. I read it straight through. I couldn’t put it down! This book is so fast paced I feel that I did everything Sadie did! This is a heart pounding book! Loved it!
July 1, 2026
Amazing!
I can’t get enough of this series and they can’t write them fast enough for me! I try so hard every time a new one comes out to stretch them out and make them last but I just can’t!
I can’t get enough of this series and they can’t write them fast enough for me! I try so hard every time a new one comes out to stretch them out and make them last but I just can’t!
July 8, 2026
Exceptional
I highly recommend the Sadie array mystery series. I have been hooked on this series since the first book and this final one was amazing. I particularly like the observations on the issues of different generations.
I highly recommend the Sadie array mystery series. I have been hooked on this series since the first book and this final one was amazing. I particularly like the observations on the issues of different generations.
July 10, 2026
Boom
I recommend that anyone who has read all of the other Sadie Gray stories should read this story. If you haven't read the other stories you won't understand the ramifications of this one and should not bother to read it until you finish Books 1 thru 11.
I recommend that anyone who has read all of the other Sadie Gray stories should read this story. If you haven't read the other stories you won't understand the ramifications of this one and should not bother to read it until you finish Books 1 thru 11.
August 16, 2026
Great series
I had a tough time with the first couple books they are very graphic. But they just keep getting better I'm sorry it's over. I hope you add more to the series highlighting the other characters.
I had a tough time with the first couple books they are very graphic. But they just keep getting better I'm sorry it's over. I hope you add more to the series highlighting the other characters.
June 19, 2026
love this book
I am a huge fan and this was fabulous. Around 25% I realized what was going on and I felt like a little kid at Christmas.
I am a huge fan and this was fabulous. Around 25% I realized what was going on and I felt like a little kid at Christmas.
June 21, 2026
This book was absolutely fantastic...loved every minute of it and was sad when it ended. This whole series is a must read but this one is my favorite. Love Sadie Gray
June 22, 2026
No words
Tying this series to my other favorite series is absolute genius. All I can say is I hope it continues for many more books.
Tying this series to my other favorite series is absolute genius. All I can say is I hope it continues for many more books.
June 22, 2026
Another good one!
Another great book in the series! I hope this is not the end of this series. I'd love to read more about Sadie and Brad. And what she decides.
Another great book in the series! I hope this is not the end of this series. I'd love to read more about Sadie and Brad. And what she decides.
June 25, 2026
Wow what a story!
I have loved all the books, but my recommendation is not to start reading at bedtime. The next time you look up its time to get up!
I have loved all the books, but my recommendation is not to start reading at bedtime. The next time you look up its time to get up!
June 25, 2026
A must read
This was the best yet. Sadie is growing up and taking charge. New characters that flesh out the story even more. I can't wait for the next one
This was the best yet. Sadie is growing up and taking charge. New characters that flesh out the story even more. I can't wait for the next one
June 25, 2026
Must Read
Another great Sadie Gray adventure! You won't be disappointed but want to read more to see where the future leads.. Can't wait for the next book!
Another great Sadie Gray adventure! You won't be disappointed but want to read more to see where the future leads.. Can't wait for the next book!
June 27, 2026
More, please!!
I’m gonna need more Sadie Gray!!! This can’t be the end of her story!! One of my most favorite characters!!
I’m gonna need more Sadie Gray!!! This can’t be the end of her story!! One of my most favorite characters!!
July 10, 2026
What an ending to the series!!!!
August 28, 2026
Great books
Great reads. Loved the characters. Couldn't put the tablet down. Went from one book to the next. Hope there's more to come.
Great reads. Loved the characters. Couldn't put the tablet down. Went from one book to the next. Hope there's more to come.
June 20, 2026
I really enjoyed this entire series. They were all fairly quick reads that sucked me in and I didn't want to put them down. This final installment had some twists I was not prepared for, but absolutely was down for them!
Displaying 1 - 20 of 20 reviews