In the Woods by Irish author Tana French is the story of two Dublin police detectives assigned to the Murder Squad. Published in 2007, this is the first book in the Dublin Murder Squad mystery-thriller series. The novel debuted to much critical praise for its intelligent plot and clever pacing. The novel’s main protagonist and narrators is Detective Adam Robert Ryan, who experienced a horrific ordeal as a child.

At age 12, Adam loses his best friends Jamie Rowan and Peter Savage while playing in the woods. Adam is eventually discovered standing in the woods with his back to a tree, his fingers digging into the bark. His shoes and socks are soaked with blood. Adam doesn’t speak for two weeks afterward and has no memory of what happened to him or his friends. Jamie and Peter are never found.

Adam’s parents move away from Knocknaree, a suburb of Dublin, where the disappearance occurred. They send their son to an upscale boarding school where he acquires a polished British accent and goes by his middle name, Rob. As an adult, Rob puts the past firmly behind him and eventually becomes a detective with the elite Dublin Murder Squad.

Rob is partnered with one of the few women on the force, Cassie Maddox. They hit it off immediately and function as a perfectly synchronized unit. For two years, the partners build an impressive track record of arrests. They also become best friends and maintain a comfortable platonic relationship. Rob frequently sleeps on Cassie’s couch when he’s too tipsy to go back to his own apartment.

Rob and Cassie are assigned to solve the murder of a 12-year-old girl named Katy Devlin. Her body is found lying on a ceremonial stone in an archaeological dig site near Knocknaree. Rob is supposed to inform his boss, Superintendent O’Kelly, that he has a past association with Knocknaree. No detective with a personal connection to a case can work on it. Rob, however, keeps silent. He hopes this case might help him solve the disappearance of his friends 20 years earlier.

The detectives interview the dig-site team and the girl’s family. Katy has a twin named Jessica and an older sister named Rosalind. The Devlin family seems devastated by the loss, but the detectives think something is off with the family dynamic.

The autopsy reveals that Katy was struck twice on the head with a rock, suffocated with a plastic bag tied around her head, and then raped with a wooden implement. Her body was stored for at least 24 hours before being left on the ceremonial stone.

Katy’s father, Jonathan, spearheads a protest group called Move the Motorway. The goal is to reroute a motorway that is supposed to plow right through the archaeological site. Jonathan has received threatening phone calls telling him to stand down. Rob and Cassie speculate that Katy’s death is an attempt to warn her father away from the cause.

As they visit the crime scene, Rob experiences flashbacks to his childhood and the final summer he spent with his friends in the woods. He feels haunted by the loss of Peter and Jamie and has frequent glimpses of memory that hover just out of conscious reach.

O’Kelly assigns a large contingent of detectives to canvas Knocknaree and take witness statements. Another detective named Sam O’Neill is assigned to work the motorway angle to find out who owns the valuable land surrounding the proposed project. Sam, Cassie, and Rob form a close bond. They cook dinner together at Cassie’s flat almost every night and spend the rest of each evening discussing the case.

At Katy’s funeral, Rosalind singles Rob out for attention. She begs him to find her sister’s killer. She later contacts Rob and wants to meet him. Rosalind tells him he will be the one to solve the case and that she has absolute faith in him. The teenager seems so fragile that Rob wants to protect her. He’s also strongly attracted to her.

As the weeks drag by, the detectives make little progress in turning up a suspect. Rob spirals downward, dragged back into unpleasant memories from his childhood. He spends a night out in the woods to see if he can remember anything that will help solve either crime.

Instead of gaining any useful insight, Rob feels the woods closing in around him and flees to the safety of his car. He’s so shaken that he can’t even drive; he calls Cassie to come pick him up. When they return to her apartment, Rob still feels anxious and wants to sleep in Cassie’s bed instead of alone on the sofa. They end up having sex.

Following this encounter, Rob is profoundly uncomfortable around Cassie and drives her away emotionally. Their working relationship deteriorates to such a degree that Rob returns to the dig site to investigate alone. While there, he remembers a small detail in a witness statement about a missing trowel. After questioning the dig workers, he’s convinced that the trowel was the implement used to rape Katy and that she was murdered right at the dig site.

The detectives and a forensics team discover blood spatters in the finds shed, which houses archaeological discoveries, and other evidence of the crime in the tool shed. Cassie and Rob identify one of the dig workers, Damien Donnelly, as the murderer.

Under questioning, Damien confesses but won’t explain his motive. He’s trying to protect Rosalind. He believes Katy was a threat to her. Cassie and Rob realize that Rosalind instigated the crime by telling Damien a wild story of abuse. Rosalind is a sociopath, and she envied all the attention Katy received as a ballet prodigy.

Cassie traps Rosalind into a confession, but the recording is inadmissible because Rosalind is still a minor. Damien is convicted of murder, but Rosalind receives a short suspended sentence. Her family moves away from Knocknaree.

Cassie and Rob never recover their lost friendship. Cassie becomes engaged to Sam instead. Rob is kicked off the Murder Squad for not revealing his connection to the missing person’s case. He never remembers what happened to his friends. In the book’s final pages, he goes back to Knocknaree to watch as the woods are cut down to make way for the motorway.