A+ #AudioBookReview: Inside Man by John McMahon

A+ #AudioBookReview: Inside Man by John McMahonInside Man (Head Cases, #2) by John McMahon
Narrator: Will Damron
Format: audiobook, eARC
Formats available: hardcover, ebook, audiobook
Genres: mystery, suspense, thriller
Series: PAR Unit #2
Pages: 390
Published by Macmillan Audio, Minotaur Books on January 13, 2026
Purchasing Info: Author's WebsitePublisher's WebsiteAmazonBarnes & NobleKoboBookshop.orgBetter World Books
Goodreads

In this sequel to McMahon's electrifying series debut, Head Cases, Gardner Camden and the PAR team return to investigate potentially connected cases.
FBI Agent Gardner Camden is an analytical genius with an affinity for puzzles. He and his squad of brilliant yet quirky agents make up the Patterns and Recognition (PAR) unit, the FBI’s hidden edge, brought in for cases that no one else can solve.
PAR’s latest case involves a militia group stockpiling weapons. When their confidential informant in the case is killed, it quickly becomes clear that the militia did not kill him.
As the squad looks into the evidence surrounding his murder, an unidentified man is caught on camera with their informant. This mystery man’s picture is connected to another case at the FBI, an unsolved series of murdered women, buried in the ground in north Florida. Could they have uncovered a serial killer? And if so, what is his connection to their C.I.?
As PAR juggles an investigation into both the dead women and the militia, they enroll a new informant, only to find the case escalating in dangerous ways. How will PAR handle a case that increasingly looks like a terrorist plot? And in the serial case, with no puzzles or witnesses, and few leads, how will a group set up to decode riddles be successful?

My Review:

The first book in this series, Head Cases, set up the characters and the structure of the FBI unit they work in, the Patterns and Recognition Unit, or PAR. They’re the ‘head cases’, the freaks, the ones who solve cold cases that defy ordinary investigative methods because something about the case isn’t ordinary – and neither are they.

PAR is also a collection of agents who have pissed off the brass in ways that are not firing offenses. Like shooting into a pattern that read F-U-C-K C-O-N-G-R-E-S-S on the wall of targets at a federal gun range, while a senator was visiting said gun range. That sort of thing isn’t a crime, it isn’t illegal, but it is guaranteed to get someone sent to the equivalent of career Siberia. Or, in the case of this series, PAR.

In Head Cases, the unit was led by a senior FBI agent named Frank Roberts. But Frank kept too many secrets from his own team in the hopes of getting a supervisory assignment back out in the wider – and more respected – parts of the FBI before the PAR Unit got closed down. He made his own escape path and kind of left the rest of ‘his’ team hung out to dry.

Except the rest of that team, spearheaded by Agent Gardner Camden, solved the serial killings, saved the day, the PAR Unit and literally saved Frank’s ass. Frank got his reward back home in Texas, and Gardner got the supervisory position, always aware that the unit was one step away from being disbanded if they didn’t deliver.

Camden, often referred to by his fellow FBI agents as THE head case among the head cases, knows that his strengths lie in figuring out the pattern and not in supervision. Or management, or office politics. He’s doing his best, working with the skills he does have, to make it work. And it mostly does.

At least until their current case threatens to blow itself sky high. They’ve spent three months following a fraud, guns and racketeering case. A big one involving fraudulent unemployment accounts – and the money paid into those accounts, illegal arms sales, and domestic terrorism – facilitated by those illegal arms sales bought with those illegally gotten funds. It’s a criminal enterprise that crosses at least one state line (Florida to Georgia and back) and has left behind a trail of bodies – and will leave more if their leader’s plans and ambitions continue on the track he’s already laid out.

The FBI’s confidential information or CI (read that as either ‘inside man’ or snitch) has heard rumors about this domestic terrorism militia purchasing several thousand kits to make ‘ghost guns’ that would have no true manufacturer or serial number. (It’s a loophole in the law and it’s being exploited, potentially to devastating effect.) It’s the FBI’s mission to find those kits and stop them from being turned into guns before they start firing.

Which is when the case goes pear-shaped. (I can’t say it goes south as they are already nearly as far south in Florida as they can get.) They find their snitch shot dead in his trailer, along with plenty of evidence, including CASH, related to the financial parts of the case.

He wasn’t shot by the people he’s snitching on, or they’d have removed the evidence. They also wouldn’t be on the way to check in with the guy and figure out why HE hasn’t been checking in. So who killed the snitch? And how can they keep the case from blowing up and taking their careers and who knows how many innocent lives, along with them?

Camden and the PAR Unit know there must be a pattern, They just have to find it. Whether or not anyone in the FBI thinks it has anything at all to do with the case they started with. Because it must.

Escape Rating A+: This is a story that I began in audio, and was certainly enjoying in audio. The narration by Will Damron was very well done and he did an excellent job of sounding like I expected Camden to sound while still giving the rest of the characters their own distinct voices. But I got caught between the dilemma that the audio was good but my reading is considerably faster, and I couldn’t stand the idea of waiting over a weekend to continue the story. So I switched to text and couldn’t put the thing down.

That being said, I picked this up in the first place because I fell headlong into the first book in this series, Head Cases, late last summer. I was absolutely riveted AND it was also a case of the ‘right book at the right time’ to the nth degree. So I grabbed the eARC of the second book up before I was even finished with the first one. I knew it was going to be THAT good. And it was.

Very much like the first book, what makes this case interesting is the way that it spirals outward in directions that no one, including the team doing the investigating, expects AT ALL. They think they’ve got one thing, and they do have to deal with that thing because the idea of a gang of domestic terrorists with ghost guns shooting up Washington DC should give anyone pause. That it particularly gives ALL the federal agencies that would either be caught in the crossfire or whose lives and careers will be toast if they fail to stop it from happening an absolute mania to catch the would-be terrorists before they strike another round of terror is exactly what one would expect. And should.

However, as big as that crime is/would be/could be, it’s not what’s driving the PAR Unit. Their search for their CI’s killer has uncovered a serial killer. Their skills at pattern recognition have unearthed several body dumping sites. They’re off on an entirely different – and not completely sanctioned – race than the one the rest of the FBI is on, yet they’re involved in both up to their necks.

It’s fascinating – and not done all that often in fiction – to see this small unit try to work two high priorities at the same time. They can’t – and in real life probably wouldn’t be – focused entirely on a single case no matter how important. Also the way that resources are allocated at the level above them shines a spotlight on how upper level priorities affect funding which affects focus on what the political powers-that-be believe is most important.

So there was a lot going on throughout this whole story, and it kept me reading long after I should have quit for the night. I had to see what happened next – and what ultimately did or did not tie the two cases together. Because they shouldn’t have been but they absolutely were.

Part of what makes the series compelling to follow are the personalities of the members of the PAR Unit itself. They each bring a whole lot of quirks, a fair bit of irreverence regarding authority, and a lot of widely different experience to the table. They do an excellent job of filling the roles of a classic “five-man band”, especially when they get their fifth member back as this story progresses.

But speaking of the characters, it’s impossible for me to read Gardner Camden’s series without thinking of George Cross’ series that begins with The Dentist. I held off on reading my next book in THAT series until I finished this book because they are a bit too similar – even though they’re not actually as much alike as one might think.

Both Camden and Cross are on the autism spectrum, and both seem to be in the same part of that spectrum. Highly intelligent, often hyper focused, with low emotional affect and engagement. In other words, what was referred to as Asperger’s syndrome not that long ago and both would have been labelled so as children as they are both in their mid-to-late 30s. Both went into police work, but Camden with the FBI in the US and Cross on a local level in Britain. It would seem like their stories should be similar, and there are similarities, but not as many as the reader might think going in as their approaches to both themselves and the world they live in are different.

Cross is aware that he is different, but he expects the world and everyone around him to bend in order to work with those differences. His world revolves around himself and he believes that everyone else should make the adjustments. Camden, very much on the other hand, while he is just as certain of who he is and how he works best, also recognizes that the world is not made for him anymore than he is made for it. He adapts as much as he can to the way things work, and is very aware of when his hyperfocus gets in the way of getting the human-facing parts of the job done. In this book he is the supervisor of the PAR Unit, and is all too cognizant of that fact that he is no good at playing politics, and that he has to find a way to be a leader for the team and a mentor for their rookie whether those things are natural for him or not, if he wants to keep the job.

So this book managed to both give me a lot to think about, as I couldn’t stop comparing Camden to Cross, at least inside the confines of my own head, and I couldn’t stop reading late into the night/morning because I had to find out not just ‘whodunnit’ but who done each of the parts of the ‘it’ the PAR Unit was following.

I had a grand reading time, so I was just a bit sorry to read at the end that the author has a lot of writing irons in the fire and while he intends to come back to PAR, he isn’t exactly sure about when. While I’ll need to look up his other series, AND look for whatever direction his work takes him, in the meantime if I want to scratch at least around this particular itch I’m glad that I have more of the Cross series to read – and most likely soon because I’ve got a book hangover that needs to be assuaged somehow.

A+ #BookReview: Head Cases by John McMahon

A+ #BookReview: Head Cases by John McMahonHead Cases (PAR Unit, #1) by John McMahon
Format: ebook
Source: purchased from Amazon
Formats available: hardcover, large print, paperback, ebook, audiobook
Genres: mystery, suspense, thriller
Series: PAR Unit #1
Pages: 341
Published by Minotaur Books on January 28, 2025
Purchasing Info: Author's WebsitePublisher's WebsiteAmazonBarnes & NobleKoboBookshop.orgBetter World Books
Goodreads

Head Cases follows an enigmatic group of FBI agents as they hunt down a murderer seeking his own justice in this electrifying—and commercial—series debut.
FBI Agent Gardner Camden is an analytical genius with an affinity for puzzles. He also has a blind spot on the human side of investigations, a blindness that sometimes even includes people in his own life, like his beloved seven-year-old daughter Camila. Gardner and his squad of brilliant yet quirky agents make up the Patterns and Recognition (PAR) unit, the FBI’s hidden edge, brought in for cases that no one else can solve.
When DNA links a murder victim to a serial killer long presumed dead, the team springs into action. A second victim establishes a pattern, and the murderer begins leaving a trail of clues and riddles especially for Gardner. And while the PAR team is usually relegated to working cold cases from behind a desk, the investigation puts them on the road and into the public eye, following in the footsteps of a killer.
Along with Gardner, PAR consists of a mathematician, a weapons expert, a computer analyst, and their leader, a career agent. Each of them must use every skill they have to solve the riddle of the killer’s identity. But with the perpetrator somehow learning more and more about the team at PAR, can they protect themselves and their families…before it’s too late?
With an enigmatic case that will keep readers on the edge of their seats and a thoroughly engaging ensemble cast, John McMahon’s Head Cases is a triumph.

My Review:

FBI Agent Gardner Camden isn’t supposed to be out in the field investigating current cases. Gardner, and his whole team, the PAR Unit (Patterns and Recognition), are the team that stays in the office and investigates the rest of the FBI’s ‘white whales’, the cold cases that haven’t been solved by more accepted methods of investigation – or more acceptable agents – but still need resolution.

All the agents in PAR, every single one of them, have an eye for detail, an ability to put the oddest pieces together into the right puzzles – and/or have pissed off the powers that be in one way or another.

PAR is career Siberia, even if it’s located in sunny Jacksonville Florida.

PAR’s cases are supposed to be ice cold and only conducted among the files, but Gardner is out in the field again because one of his old, cold cases has turned suddenly and unexpectedly hot. A serial killer is dead. That’s not why the case is hot. The case is hot because that serial killer was declared dead years ago, in a case that Gardner closed himself – because the killer was dead.

Turns out he wasn’t. But he is NOW. Meaning that someone found a man the FBI hadn’t been able to find – and killed the one they let get away. The one that Gardner let get away.

Just as Gardner reopens THAT old case, another serial killer gets his just desserts halfway across the country. But this one hadn’t gotten away. He’d served his time, paid his debt to society, and was released to live out his remaining, declining, years. Whether he’d have killed again in his old age was certainly a possibility – but it hadn’t happened yet. It hadn’t even had time to happen.

Leaving PAR and its ensemble of misfit agents on the trail of a serial killer who kills serial killers, using not his own methods but the just desserts of killing each killer by using each killer’s own methods to make his point.

He’s also made the point that he’s on the inside, reading their files, following their tracks. Either he’s breached the FBI’s highly vaunted security – or he’s already inside it.

All PAR has to do is put together all those patterns and recognize not only whodunnit but why and how. What made THIS serial killer blow, and what they need to do to protect themselves and their loved ones even as the FBI threatens to pull the plug on their case and their careers to protect itself from an enemy within.

Escape Rating A+: I picked this up this week because the book I planned to read was really fluffy and it just wasn’t what I was in the mood for. What I wanted was something a bit darker and grittier, which led me right to the mystery/suspense/thriller section of the virtually towering TBR pile.

This is the book that reached out and grabbed me – and it was absolutely the right book at the right time.

I often have kind of a love/hate relationship with thrillers. I get caught up in the pacing, I love the chase, I adore that the characters who are doing the chasing are often very good at their jobs. In other words, they generally hit my kink for competence porn squarely on the nose.

The problem I have is that the motivation for the thriller is often something I don’t want in my head. Things I absolutely do recognize exist but that I don’t want to be fully immersed in. Things like domestic violence, stalking, and serial killers.

And yes, I know I just contradicted myself. But this is a story about serial killers told from the perspective of the police hunting them down. We’re never inside the killers’ heads – which is the place I don’t want to be AT ALL.

So the process of this one reads like a police procedural – just one where the clock is ticking very loudly because the perpetrator keeps on perpetrating at a fast clip and fully intends to keep right on doing it until he gets stopped by the investigators – who he is also targeting.

In that sense, Head Cases reminded me a lot of the Quinn & Costa and Forensic Instincts series, both series where highly competent teams chase down serial killers or other equally dangerous and deadly repeat criminals. Head Cases hit a thriller sweet spot that I got caught up in from the very first page and didn’t let me go until the righteous and cathartic end.

Gardner, in particular, also gave me vibes of Miranda Chase from her Miranda Chase NTSB series. Both characters see the world a bit differently due to neurodiversity, and both use their differences as strengths in their chosen fields. I’m very glad to have found another protagonist whose adventures and investigations are utterly absorbing – and I like both of their ‘Scooby gangs’ very much.

Head Cases turned out to be an edge-of-the seat compelling read for this somewhat thriller-adverse reader. I’m thrilled (yes, pun definitely intended) to say that there’s a second book in the series, Inside Man, coming out in January. I’m looking forward to seeing PAR tackle another case as well as, perhaps, getting stuck into the mess that the FBI has made of itself at the end of this book.