Lars Kepler’s The Sandman is the kind of action-packed book that will have readers nibbling their nails as they read the short, sharp chapters, bouncing back and forth between the two main characters and the trail of bodies they find.

Detective Joona Linna has lost more than his family in tracing the serial killer, Jurek Walter, who languishes in a secure psychiatric facility after Linna caught him. But the detective has always maintained that Walter couldn’t have pulled off the family-linked murders he’s in prison for without an accomplice.

One man who’s lost his children to Walter is Reider Frost, a renowned author–until his son Mikael is found wandering a railroad track, emaciated and confused. Thirteen years ago the boy and his sister were both abducted and feared dead, but finding Mikael confirms what Linna has felt: that some victims were often kept alive, under cruel conditions, until their deaths.

When Mikael recovers enough to tell police his sister, Felicia, is also still alive, a race starts to find the young woman. Linna will enlist the help of agent Saga Bauer to enter the hospital undercover where Walter is being held as a patient. Her goal is to post as a schizophrenic patient and plant a microphone to record any conversations she has with Walter, in hopes of obtaining clues to his accomplice and his hideout.

It’s a highly charged cat and mouse game. Walter is a genius at manipulation, making Linna use every bit of his intelligence and his intuition to outsmart the killer, if such a thing is possible, as the body count rises to a startling climax.

This is the sixth Linna novel, written by a husband and wife writing team of novelists under the pen name of Lars Kepler. One can only wish to be a fly on the wall during their daily writing routine, developing the twisted, unrelenting plot, and these characters whose fates hang in the balance.