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An AJ Docker and Banshee Thriller #2
Faulty Bloodline
"A well-crafted, fast-paced medical crime thriller that will put you in the middle of the ER, holding your breath. The plot will unfold and suck you right in. And, as a bonus, there's a great dog!" –Jeffrey Jay Levin, author of Watching
AJ Docker (Doc) and his guard dog, Banshee, move to a small town in the mountains for a slower-paced lifestyle. Doc settles into the idyllic setting with a rewarding job and enriching colleagues, as well as with a romantic interest who leads him to contemplate marriage. His new life seems perfect until he begins to uncover the town's dirty secrets. A serial killer hunts in the woods, and dirty money flows throughout the town.
Doc and Banshee win allies in their search for truth, but they also make powerful enemies. These sophisticated figures who control the town's economy will stop at nothing to end Doc's threat to expose them. Doc must fight for his freedom, and even for his life to escape.
Faulty Bloodline, a fast-paced thriller, continues the adventures of Doc and Banshee that began in Last Patient of the Night. Gary Gerlacher's writing will keep you up late into the night as you want to keep reading the next page.
AJ Docker (Doc) and his guard dog, Banshee, move to a small town in the mountains for a slower-paced lifestyle. Doc settles into the idyllic setting with a rewarding job and enriching colleagues, as well as with a romantic interest who leads him to contemplate marriage. His new life seems perfect until he begins to uncover the town's dirty secrets. A serial killer hunts in the woods, and dirty money flows throughout the town.
Doc and Banshee win allies in their search for truth, but they also make powerful enemies. These sophisticated figures who control the town's economy will stop at nothing to end Doc's threat to expose them. Doc must fight for his freedom, and even for his life to escape.
Faulty Bloodline, a fast-paced thriller, continues the adventures of Doc and Banshee that began in Last Patient of the Night. Gary Gerlacher's writing will keep you up late into the night as you want to keep reading the next page.
275 pages, Kindle Edition
First published March 14, 2024
3298 people are currently reading
1110 people want to read
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Displaying 1 - 30 of 346 reviews
September 28, 2025
The second book in the series and I really enjoy the writing style as I get a Reacher vibe. Multiple mysteries and loaded with action I read the book over 2 days. The book is written by a physician, so it feels very authentic. The quibbles that I had with the plot are how some of the characters react to some soul crushing actions by others. It felt a bit off. Another plot device is having a service dog making rounds with the Dr but this is fiction, so I got over it. I plan to read the next book and recommend the series if you want action and good ole fashion country lawyer that is smart as can be with a Dr who owns a loveable working police dog.
September 17, 2025
Love love AJ!
So Aj find himself in a small town with hidden secrets! His dog tags along with him and he ends up falling for the Otho surgeon who just happens to be related to the Sherriff. But when AJ starts to get too close to the truth buried under the town's history. He may just be paying a hefty price when it comes to his heart!
Family is sometimes more dangerous than we could ever imagine!
Solid 4.5 stars!!!!
So Aj find himself in a small town with hidden secrets! His dog tags along with him and he ends up falling for the Otho surgeon who just happens to be related to the Sherriff. But when AJ starts to get too close to the truth buried under the town's history. He may just be paying a hefty price when it comes to his heart!
Family is sometimes more dangerous than we could ever imagine!
Solid 4.5 stars!!!!
May 13, 2024
I saw the cover of this book and I was like "If something happens to my boy Banshee I'm ripping my phone in half and deleting kindle forever". Not really a spoiler since a third part in the trilogy called AJ Docker and Banshee is due to be released in June, my phone is safe.
I'll start with the bad stuff
1. Once again Doc is a superhuman capable of espionage, seduction and more heart than a regular James Bond. Gives alot of plot armor and makes the story almost supernatural.
2. There is something very juvenile about description of characteristic. It's like a teenage with raging hormones describing people.
THE GOOD STUFF (SO GOOD THAT DESPITE WHAT I DISLIKED ABOUT THE NOVEL I GAVE IT A 5/5).
1. The storyline was amazing, although there were no twists.
2. BANSHEE HAS MY WHOLE HEART AND HE CAN KEEP IT FOREVER
3. We get to see alot more of Doc's Captain America nature, a huge leap from the douche that I assumed him to be in the beginning of the first book.
4. The humor was alot better and character building was at its peak.
5. Loved the scenic description of a small town village (a very personal opinion as a I love small town thrillers).
6. I also enjoyed how this book changed genres in the last stretch, and, yet, the transition was smoother than the creamiest peanut butter that I've had.
Can't wait for part 3 in June
I'll start with the bad stuff
1. Once again Doc is a superhuman capable of espionage, seduction and more heart than a regular James Bond. Gives alot of plot armor and makes the story almost supernatural.
2. There is something very juvenile about description of characteristic. It's like a teenage with raging hormones describing people.
THE GOOD STUFF (SO GOOD THAT DESPITE WHAT I DISLIKED ABOUT THE NOVEL I GAVE IT A 5/5).
1. The storyline was amazing, although there were no twists.
2. BANSHEE HAS MY WHOLE HEART AND HE CAN KEEP IT FOREVER
3. We get to see alot more of Doc's Captain America nature, a huge leap from the douche that I assumed him to be in the beginning of the first book.
4. The humor was alot better and character building was at its peak.
5. Loved the scenic description of a small town village (a very personal opinion as a I love small town thrillers).
6. I also enjoyed how this book changed genres in the last stretch, and, yet, the transition was smoother than the creamiest peanut butter that I've had.
Can't wait for part 3 in June
March 12, 2025
I’m really liking this author- easy quick medical and detective stories
May 31, 2025
⭐ 3/5 ⭐
I was a bit disappointed by this book. I might have high expectations after the first one.
This second book is flat, foreseeable, less funny, less endearing characters (even though Banshee and Travis are the best).
Also, I found people's grief in this book very odd or unrealistic.
The book was easy to read, and I still enjoyed the investigation part.
I was a bit disappointed by this book. I might have high expectations after the first one.
This second book is flat, foreseeable, less funny, less endearing characters (even though Banshee and Travis are the best).
Also, I found people's grief in this book very odd or unrealistic.
The book was easy to read, and I still enjoyed the investigation part.
December 7, 2025
While I appreciate the accuracy of the medical situations I find other aspects to be shallow. I guess if you fall in love in 2 days then you don’t mourn very deeply when she dies.
This entire review has been hidden because of spoilers.
February 11, 2025
The Faulty Bloodline is book two in the A.J. Decker Medical Thriller Series by Gary Gerlacher, MD. After book one in the series, I didn't think this author could write a book that would draw me in quicker than before. However, I was wrong; the author produced an exceptional read with a fantastic plot and excellent characters that you either love or absolutely hate and can get even the coldest hearts in their feelings. And, of course, Banshee is still my favorite character, but Travis quickly became my second favorite. I highly recommend this author and this series to anyone who enjoys reading thrillers.
January 21, 2025
I am hooked on Gary Gerlacher!
Very nice read that kept me wanting to see what the next page brought! My second book to read and can’t wait to start the next one!
Very nice read that kept me wanting to see what the next page brought! My second book to read and can’t wait to start the next one!
September 21, 2025
3.5 - quick read, liked this one better than the first book
February 18, 2024
Gripping,
Faulty Bloodline by Gary Gerlacher is totally gripping, well written, and entertaining. It grabs you from the 1st page to the end. The story fallows the main character Dr. AJ Docker (Doc), and his dog Banshee (Belgian Malinois) at a 3 month job at a hospital in a small town in Montana.. There they meet a bunch of very interesting characters leading to many twists, and turns. Great flow, fast paced, and thourougly delightful. It had my attention from the 1st page.
Faulty Bloodline by Gary Gerlacher is totally gripping, well written, and entertaining. It grabs you from the 1st page to the end. The story fallows the main character Dr. AJ Docker (Doc), and his dog Banshee (Belgian Malinois) at a 3 month job at a hospital in a small town in Montana.. There they meet a bunch of very interesting characters leading to many twists, and turns. Great flow, fast paced, and thourougly delightful. It had my attention from the 1st page.
March 7, 2025
Second in the series……and I’m not complaining. Doc remains an awesome main character. Despite a move to a different state, he still manages to encounter some pretty significant goons and manages to stir up some big trouble. He puts some much more admirable effort into a relationship in this one, and without “spoiling”, I must say I did not like how this turned out. Looking forward to the next one. PS I would take a dog like Banshee in my world any day of the week.
February 26, 2025
Okay, glad I kept going because this one was good!!! It kind of solidified that Doc is just a guy who butts in where he doesn't belong, but because he is trying to do what's right. This one had more my kind of relationships, drama, and plot twists!
September 27, 2025
Book 2 of this series!
I loved it and couldn’t easily put it down. I kept going back to it to read some more and finished easily in 48 hours. Gary Gerlacher is my new favorite author and I am now moving on to the 3rd book in the AJ Docker series!
I loved it and couldn’t easily put it down. I kept going back to it to read some more and finished easily in 48 hours. Gary Gerlacher is my new favorite author and I am now moving on to the 3rd book in the AJ Docker series!
December 7, 2025
fast paced and loved it
This is the second book I’ve read in this series. Couldn’t put the book down. For sure fell in love with Banshee.
This is the second book I’ve read in this series. Couldn’t put the book down. For sure fell in love with Banshee.
October 24, 2025
I absolutely love Doc and banshee. this is such a good series! I already have book 3 on hold.
Definitely a must read!
Definitely a must read!
February 16, 2025
I am enjoying this series about a traveling ER doctor who seems to enjoy getting involved in police investigations which often put him in danger. A quick read with an interesting ending.
November 20, 2025
3.5 stars
I didn't like AJ as a character with the previous book so I was hoping the second book would have him as a better character. AJ wasn't the cocky know it all man character, it was toned down a lot for this book. The first half of the book the character grated my nerves a bit but the last half I started to like him a bit more. I think it was because he wasn't invincible and couldn't "Macgyver" his way out of everything. I'll give the next book a listen and hope this character has more development and less cockiness.
Narrator was good, listened at 2.5 speed.
I didn't like AJ as a character with the previous book so I was hoping the second book would have him as a better character. AJ wasn't the cocky know it all man character, it was toned down a lot for this book. The first half of the book the character grated my nerves a bit but the last half I started to like him a bit more. I think it was because he wasn't invincible and couldn't "Macgyver" his way out of everything. I'll give the next book a listen and hope this character has more development and less cockiness.
Narrator was good, listened at 2.5 speed.
November 16, 2025
Just a Great Read !!!
A well written adventure, outstanding character development, with just enough happiness and tragedy to keep me looking for book 3 !! (I would have liked to see Doc settle here but maybe in the next book).
Thanks to Gary Gerlacher !! Consider me a FAN !!
A well written adventure, outstanding character development, with just enough happiness and tragedy to keep me looking for book 3 !! (I would have liked to see Doc settle here but maybe in the next book).
Thanks to Gary Gerlacher !! Consider me a FAN !!
June 9, 2025
Researched?
This book was a struggle since the plot was obvious and the book not well researched. I didn't realize it was book 2 of a series but that wasn't an issue since I have read book 1 and frankly wasn't a fan.
This book was a struggle since the plot was obvious and the book not well researched. I didn't realize it was book 2 of a series but that wasn't an issue since I have read book 1 and frankly wasn't a fan.
November 12, 2025
Still giving me Emily Slate vibes! I did know who done it immediately, but there were a couple twists in there to keep me going. 3.5 rounded up to 4. Gonna keep reading this series!
August 29, 2024
Predictable
One quarter of the way into the ,book and you know who, what and where. My favorite part is the dog. AJ is ok but can't decide if he is a doctor or PI. Hence the next book
One quarter of the way into the ,book and you know who, what and where. My favorite part is the dog. AJ is ok but can't decide if he is a doctor or PI. Hence the next book
January 11, 2025
Good sequel to first book
I think the author should have included more grief for the supposed Loss of the love of Doc's life. Made him seem coldly cavalier about it in jail. Really stood out to me. Too few tears too late at the very end.
I think the author should have included more grief for the supposed Loss of the love of Doc's life. Made him seem coldly cavalier about it in jail. Really stood out to me. Too few tears too late at the very end.
February 28, 2025
”Faulty Bloodline” by Gary Gerlacher had an interesting premise but failed to deliver. The pacing was uneven, characters felt flat, and the plot was predictable. The writing style also didn’t capture my attention. Overall, a letdown.
December 11, 2023
ER meets Longmire
If my loved one needed an Emergency Room doctor, I’d want the cockiest, most self-assured physician in the hospital on the case. That prerequisite is fulfilled in Dr. AJ Docker; Doc to his friends.
Faulty Bloodline is the second book in the AJ Docker and Banshee series, but it stands alone perfectly well. I look forward to reading Last Patient of the Night, the first book, but I haven’t yet, so I don’t have the origin story of this badass dynamic duo. Still, I willingly and easily suspended disbelief in the opening chapters when Doc sent his retired police dog into an active shooter scene with the blessing of local law enforcement to whom Doc and his dog Banshee are strangers. Doc is described as someone who “sticks his nose where it doesn’t belong,” but if he kept his nose to himself, bad things would happen and we readers wouldn’t have any fun.
Banshee is a proper superhero, as are all K-9 LEOs. My labradoodle is pretty tired of me comparing him to the impeccably trained crime fighter in the book. Banshee is the best literary sidekick of all time. I said what I said.
I enjoyed the ER drama and being in the room with the docs; even learned a few things that might come in handy. Gerlacher expertly guides us behind the doors of the ER and OR, where he is as comfortable as the rest of us are in our living rooms. The imagery of Montana ranchland creates the vibe of wide-open spaces, but even the most peaceful settings can’t dissuade the dark side of humanity. Criminals are gonna crime and the justice system is gonna process them, and we readers get to tag along as the perps are caught and tried.
I read Faulty Bloodline in two sittings. The book was a fast-paced, fun adventure with a satisfying ending. While I wait for the third book in the series, I’ll read the first. My doodle hasn’t heard the last of his owner praising the fictitious Banshee.
If my loved one needed an Emergency Room doctor, I’d want the cockiest, most self-assured physician in the hospital on the case. That prerequisite is fulfilled in Dr. AJ Docker; Doc to his friends.
Faulty Bloodline is the second book in the AJ Docker and Banshee series, but it stands alone perfectly well. I look forward to reading Last Patient of the Night, the first book, but I haven’t yet, so I don’t have the origin story of this badass dynamic duo. Still, I willingly and easily suspended disbelief in the opening chapters when Doc sent his retired police dog into an active shooter scene with the blessing of local law enforcement to whom Doc and his dog Banshee are strangers. Doc is described as someone who “sticks his nose where it doesn’t belong,” but if he kept his nose to himself, bad things would happen and we readers wouldn’t have any fun.
Banshee is a proper superhero, as are all K-9 LEOs. My labradoodle is pretty tired of me comparing him to the impeccably trained crime fighter in the book. Banshee is the best literary sidekick of all time. I said what I said.
I enjoyed the ER drama and being in the room with the docs; even learned a few things that might come in handy. Gerlacher expertly guides us behind the doors of the ER and OR, where he is as comfortable as the rest of us are in our living rooms. The imagery of Montana ranchland creates the vibe of wide-open spaces, but even the most peaceful settings can’t dissuade the dark side of humanity. Criminals are gonna crime and the justice system is gonna process them, and we readers get to tag along as the perps are caught and tried.
I read Faulty Bloodline in two sittings. The book was a fast-paced, fun adventure with a satisfying ending. While I wait for the third book in the series, I’ll read the first. My doodle hasn’t heard the last of his owner praising the fictitious Banshee.
October 30, 2025
Faulty Bloodline by Gray Gerlancer
4.5 ⭐ ⭐ ⭐ ⭐ ✨
Trigger warning: The book opens with a disturbing murder scene and later includes a school shooting. I’m not sure both were needed, except perhaps to highlight the author’s focus on mental health and its far-reaching impact.
Despite the heavy subject matter, the mystery is so gripping that I stayed up all night to finish it. Faulty Bloodline continues the story of Doc, an ER physician whose compassion and curiosity often pull him far beyond hospital walls. When a string of suspicious deaths stirs up old secrets, he finds himself once again caught between saving lives and uncovering the truth.
Banshee, his loyal K-9 companion, remains the hero of the hour—brave, intuitive, and every bit the heart of this series. Doc continues to care deeply for his patients while giving readers an authentic look at both the medical and emotional realities of emergency medicine. Sure, he acts like a wannabe cop in some ridiculously unsanctioned ways, but it adds to the tension and excitement rather than distracting from it.
This is a mystery with a strong pulse of thriller energy—fast-paced, high-stakes, and emotionally charged. It keeps you guessing to the end and leaves you eager for the next installment. A bingeable series for sure.
4.5 ⭐ ⭐ ⭐ ⭐ ✨
Trigger warning: The book opens with a disturbing murder scene and later includes a school shooting. I’m not sure both were needed, except perhaps to highlight the author’s focus on mental health and its far-reaching impact.
Despite the heavy subject matter, the mystery is so gripping that I stayed up all night to finish it. Faulty Bloodline continues the story of Doc, an ER physician whose compassion and curiosity often pull him far beyond hospital walls. When a string of suspicious deaths stirs up old secrets, he finds himself once again caught between saving lives and uncovering the truth.
Banshee, his loyal K-9 companion, remains the hero of the hour—brave, intuitive, and every bit the heart of this series. Doc continues to care deeply for his patients while giving readers an authentic look at both the medical and emotional realities of emergency medicine. Sure, he acts like a wannabe cop in some ridiculously unsanctioned ways, but it adds to the tension and excitement rather than distracting from it.
This is a mystery with a strong pulse of thriller energy—fast-paced, high-stakes, and emotionally charged. It keeps you guessing to the end and leaves you eager for the next installment. A bingeable series for sure.
June 28, 2025
Great plot in AJ Docker & Banshee Thriller Book2
Book1 in the AJ Docker Medical Thriller series by Gary Gerlacher has a pretty good plot, but book 2’s plot is even better! Both books have helped me get back into reading, after taking a year off from that hobby, and watching television instead. I consciously made the switch last summer because of the massive political tension that I was feeling as we got closer to Election Day 2024. I felt books were not giving me enough of an escape from real life—-and I really needed some mindless TV to take me away from reality. But I have missed reading!! This series had so many good reviews that I decided to give it a try, and I am so glad I did. Both books have solid plots, elements of serious medical and legal happenings, interesting descriptions of people, scenery buildings, etc, with humor thrown in to lighten the serious situations. All in all, exciting reads that have left me grateful for dedicated doctors, talented lawyers, honest judges, and protective guard dogs. Yay Banshee! Can’t wait to read the other books in the series!!
Book1 in the AJ Docker Medical Thriller series by Gary Gerlacher has a pretty good plot, but book 2’s plot is even better! Both books have helped me get back into reading, after taking a year off from that hobby, and watching television instead. I consciously made the switch last summer because of the massive political tension that I was feeling as we got closer to Election Day 2024. I felt books were not giving me enough of an escape from real life—-and I really needed some mindless TV to take me away from reality. But I have missed reading!! This series had so many good reviews that I decided to give it a try, and I am so glad I did. Both books have solid plots, elements of serious medical and legal happenings, interesting descriptions of people, scenery buildings, etc, with humor thrown in to lighten the serious situations. All in all, exciting reads that have left me grateful for dedicated doctors, talented lawyers, honest judges, and protective guard dogs. Yay Banshee! Can’t wait to read the other books in the series!!
December 11, 2023
AJ “Doc” Docker is a very likeable character who despite trying to do the right thing is dealt a raw deal. But with the help of a sharp local attorney, an equally engaging character, Doc fights for justice.
However, it is Doc’s sidekick Banshee, a highly-trained ex-law enforcement K9, who is the star of the show. I am forever spoiled now and I want a Banshee in every book I read!
This twisty plot with realistic courtroom drama and tricky evidence is superbly written, with just the right balance of science and fact to make it believable, but not so much as to bog the reader down with confusing data.
You can’t help but cheer on Doc and Banahee as their adventure takes them on a chilling journey through a small town rife with secrets.
Although Faulty Bloodline can be read as a stand alone, it has me excited to read the first book in this series of addictive characters, The Last Patient of the Night.
However, it is Doc’s sidekick Banshee, a highly-trained ex-law enforcement K9, who is the star of the show. I am forever spoiled now and I want a Banshee in every book I read!
This twisty plot with realistic courtroom drama and tricky evidence is superbly written, with just the right balance of science and fact to make it believable, but not so much as to bog the reader down with confusing data.
You can’t help but cheer on Doc and Banahee as their adventure takes them on a chilling journey through a small town rife with secrets.
Although Faulty Bloodline can be read as a stand alone, it has me excited to read the first book in this series of addictive characters, The Last Patient of the Night.
June 6, 2025
Another excellent book in the AJ Docker & Banshee series. This time Doc has completed his hospital rotation in Dallas and has moved on to a much smaller town in Montana as they travel Westward. Banshee is traveling with Doc both for protection and as a companion. He was recently retired from the FBIs K9 unit. As we've seen in the 1st book trouble seems to follow Doc wherever he goes. And in this book he gets tangled up in a big mess. The main characters are fully fleshed out although, we as the reader learn more interesting facts about AJ "Doc" Docker. This book is hard to put down and definately a nail-biter. Plenty of murder and mayhem to keep the reader busy all the way up to the end of the book. I gave Faulty Bloodline 5☆s as it more than met my expectations. I look forward in reading the next book in the series; Sin City Treachey. Trouble and mayhem seems to follow this character so I look forward to the mess Doc & Banshee will dredge up in the next book.
December 3, 2023
Lassie was one boy’s friend—Banshee is every reader’s newest hero and every bad guy’s worst nightmare! Gerlacher nails his sophomore thriller effort with “Faulty Bloodline!”
AJ “Doc” Docker and his loyal dog, Banshee, unravel a web of deceit in a medical/legal page-flipper set in a Montana small town. Gerlacher crafts a fast-paced narrative, seamlessly blending Doc's quest for love with the ominous discovery of a serial killer and corruption lurking beneath the town's surface. As alliances meld and enemies surface, the stakes skyrocket, pushing Doc and Banshee to fight—not just for truth but for their own survival.
With compelling characters and relentless suspense, “Faulty Bloodline” will steal your waking hours. Although the novel is the second in Gerlacher’s series (I’ll be going back to read the first,) he has deftly written this story to stand alone for new readers.
AJ “Doc” Docker and his loyal dog, Banshee, unravel a web of deceit in a medical/legal page-flipper set in a Montana small town. Gerlacher crafts a fast-paced narrative, seamlessly blending Doc's quest for love with the ominous discovery of a serial killer and corruption lurking beneath the town's surface. As alliances meld and enemies surface, the stakes skyrocket, pushing Doc and Banshee to fight—not just for truth but for their own survival.
With compelling characters and relentless suspense, “Faulty Bloodline” will steal your waking hours. Although the novel is the second in Gerlacher’s series (I’ll be going back to read the first,) he has deftly written this story to stand alone for new readers.
March 3, 2025
More Jack Reacher elements in this second book in the series with Doc Docker heading out on the road, calling no place home but putting in short term ER jobs to fund his travels. In Montana he makes an instant connection with a talented, beautiful orthopedic doctor, and on a hiking outing they stumble on a burial site, thanks to Doc’s dog Banshee who fetches a skeletonized hand. With Banshee’s help, the police find several more burial sites and discover the peaceful town appears to be harboring a serial killer. Doc feels responsible, having found the initial site, to find justice for these buried people. Not to mention his curiosity and problem-solving character traits that get him into plenty of trouble. Less medical elements in this second book (which I missed) and more adventure, thriller focus.
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