Receiving a sealed bottle with a years-old plea for help by two young victims imprisoned in a boathouse by the sea, Detective Carl Morck follows leads to a desperate woman trapped in a brutal marriage to a man who keeps her in isolation and hides deadly secrets.

"In the penultimate thriller of the New York Times and #1 internationally bestselling Department Q series, the team must hunt for a nefarious serial killer who has slipped under the radar for decades. On her sixtieth birthday, a woman commits suicide. When the case lands on Detective Carl Mørck's desk, he can't imagine what this has to do with Department Q, Copenhagen's cold cases division. It's a tragedy to be sure, but the cause of death seems...