‘The Secret Place’ by Tana French

Tana French works small. In her prize-winning crime novels, the Irish author focuses on details rather than broad strokes or action. A troubling childhood memory, a recurring report of a strange noise, or an abandoned suitcase have all served as the keys for solving the mysteries of her books, which are often more about the characters than the crimes. In French’s latest, “The Secret Place,” the telling detail is a note — and that epitomizes both the promise and the failure of this uneven fifth outing.

The note is a simple thing. “I know who killed him,” it reads in letters clipped out of a magazine, as if for a ransom. The words are pasted on a photo of Chris Harper, a handsome boarding-school teenager who had been found bludgeoned to death on the grounds of the neighboring girls school the year before. The recipient is Detective Stephen Moran, who had a minor role in French’s “Faithful Place.”

Moran is stuck in cold cases but lusts for a job on the murder squad. When young Holly Mackey — daughter of Detective Frank Mackey, whose past came to light in that previous book — brings him the note, which had been posted on a school message board, he sees his chance for promotion. He uses it as leverage to work with the odd-girl-out in murder, Detective Antoinette Conway, whose frosty demeanor is as much about her fear of failure as it is self-protection in this macho world. The two slowly bond as they interview the girls at Holly’s school.

Their dynamic — powered by aspiration, fear, and a certain sexual tension — mirrors what they find at St. Kilda’s, the school that Holly attends and where Chris was killed. From the start, both realize that the note cannot be trusted. Like all the narratives they will hear, it may be a lie — or wishful thinking. Or even, Moran comes to suspect, the result of the complicated interaction between desire and rivalry that characterizes these adolescents’ lives.

In the day-long investigation that fills the book, the detectives interview members of two different St. Kilda cliques. Both groups exhibit intense loyalty and rigid hierarchies, although both are being strained as their members grow and change. One is more conventional and obsessed with clothes, makeup, and the boys at St. Colm’s, which Chris had attended. The second group, of which Holly is a part, is a little different.

The flashbacks interspersed with the present-day action explain why. They begin several months before the murder, with the arrival of Holly as a boarder. The period they cover is a crucial one in the girls’ lives, as they navigate the passionate friendships and emerging sexuality of adolescence. The neighboring schools are nominally Catholic, but the teenagers face very few constraints as they interact through sexually explicit text messages and in the weeds behind the local shopping mall. It is through these texts, as much as the interviews, that the two detectives ultimately come to understand the passions, abuse, and loyalties behind the crime.

French often writes beautifully, capturing the teen appeal of a boy’s “hard-cut mouth electric with maybe kisses.” When she lets the girls speak for themselves, however, this evocative prose disappears. When one girl attempts to explain a school project, for example, we are treated to the following: “It’s about, like, how people see themselves differently because of the media and the internet? Or something; it wasn’t my idea.” The author’s goal may be realism, but the result is the opposite: flattening out these characters to the point where several minor players become nearly indistinguishable.

In a novel of character, the reliance on these texts — and the resulting lack of clarity — is a serious flaw. It doesn’t kill the magic but it does slow the pace of what could have been another French triumph.