In the Woods

I have had this inaugural outing by mystery/thriller writer Tana French in my library for ages and did not read it until now, prodded by my mystery book group's selection of it for this month's read. I had recently read The Trespasser, a later entry into her Dublin (Ireland) "Murder Squad" books, and found her writing to be exquisite and her characterizations, plotting, dialogue, and scene setting to be outstanding. She occasionally has overlap of characters from one book to another, but they are always told from a different character's perspective.
Here we meet Cassie Maddox and Rob Ryan, two of the youngest and newest detectives on the elite Murder Squad. Although originally paired with other partners, they have now been working together for several years, and have developed such a finely tuned tapestry of thought, talk, and action that their solve rate exceeds many of the more senior detectives. Ryan has a secret that only Cassie knows. He was one of three 12-year-old children who one summer day went into the woods near a somewhat remote housing estate, Knocknaree. He was found a day later, his shoes full of blood, scratches down his back, and absolutely no memory of what happened to his best friends, Jamie and Peter.  His family subsequently moved and sent him to boarding school where he grieved, then adapted, developed an English accent, stopped using his first name, and, after finishing school, wandered aimlessly through life until he decided to enter the police academy. Cassie has never told anyone her secrets, but Ryan is OK with that. They are, contrary to all expectations and gossip, not romantically involved, but they are best friends.
When a 12-year old girl is found murdered on an archaeological dig near the same housing estate where Ryan's childhood friends disappeared, he and Cassie take the case, agreeing not to reveal to their superior the potential conflict of interest.  But in spite of best efforts, they cannot find the killer, the evidence connecting this murder to the earlier disappearances is tissue thin, and, in spite of all Ryan's efforts, the memories still refuse to come. But he does begin to spiral down into a black hole, sucked into defending the sister of the victim against all Cassie's warnings. He ultimately does something that, worse than jeopardizing the case, threatens his relationship with Cassie. Even though he ultimately figures out who has killed the girl, there are so many negative repercussions of his behavior that his future with the Murder Squad is at an end... a tragic outcome.
Reviews available from The New York Times (brief), The Guardian, Publishers Weekly, Kirkus (also brief), and that from The New Yorker places this book within the context of French's entire oeuvre.