The Watcher in the Wall by Owen Laukkanen

G.P. Putnam’s Sons, 362 pages, $27

FBI agent Carla Windermere has revved her engines and hunted all sorts of perps in four previous books by Owen Laukkanen. “The Watcher in the Wall” is the fifth and the one with the most personal resonance for Windermere.

Although she grew up in Florida, Windermere, along with her partner Kirk Stevens, is headquartered in the Twin Cities in Minnesota. Because of her prior successes, she is known as the “supercop.” She even has a boyfriend, another agent, Derek Mathers. She is pretty well acclimated by now. And happy, as much as it is within her capacity to be.

A schoolmate of Stevens’ teenaged daughter committed suicide. Adrian Miller had an Internet partner, another teen interested in suicide. Adrian gave this teen the courage she needed to commit suicide herself by going first. And by streaming it via webcam to her. The connection is brought to light when Adrian’s computer is laid bare by the FBI. It’s also brought to light that Adrian was bullied at school. Shunned by all, physically abused, Adrian’s only solace was the suicide forum. After he is dead, it is too late to tell him that he has been conned.

Windermere, it turns out, has a personal reason to want to catch whoever is taking advantage of vulnerable teens. It’s a poignant remembrance that brings Windermere to her latest mission, and she takes off with a vengeance.

“The Watcher in the Wall” is a thrilling cat-and-mouse game between the anonymous cyberbully and the FBI. It’s an uncovering of the anguish of teens who are judged lowest on the social totem pole. It’s a soul-wrenching search by a woman with a dark shadow in her past.

Laukkanen gives us the gift of great pacing. He doesn’t sacrifice his characterizations either. We do find out fairly early who the cyberbully is, and we hear the sad tale behind that. Also, it was refreshing to read a straightforward book with no narrative tricks. (Although I have enjoyed a good many books with creative twists.)