A mummified corpse is accidentally found in a cellar on Norderney. It quickly becomes clear that a serial killer has repeatedly walled up young women here and left them to die of miserable thirst in their dungeon. The “Soko Maurer” has been investigating for years.
How many walled-in people are still waiting for them and what is the perpetrator’s motive? The head of the Soko has heard of Chief Inspector Ann Kathrin Klaasen in East Frisia, who has already succeeded in putting a stop to two serial killers using completely unorthodox methods. He relies on her excellent intuition, a great honor for Kripochef Ubbo Heide. But when a young woman from Leer disappears without a trace and a gynecologist is forcibly abducted, Ann Kathrin is forced to act.
Without further ado, she decides to conduct an unusual self-experiment: Her neighbor and longtime friend, bricklayer Peter Grendel, is not even surprised when Ann Kathrin asks him to wall her in. Her colleague and partner Weller tries to talk her out of it, but she persists. After all, the criminological-scientific investigation methods have not brought them one step further so far!
There is not much time to put the pieces of the puzzle together to form a picture, because on the third day without water, the lives of the last two victims in their dark dungeon hang only by a thread…