A mummified body is accidentally found in a basement on Norderney. It quickly becomes clear that a serial killer repeatedly walled in young women. He miserably thirsty her in her dungeon. The „ Soko Maurer " has been determining for years. How many walled people are still waiting for them, and what is the perpetrator's motive? The head of the Soko, Wolfgang Huberkran, heard from main commissioner Ann-Kathrin Klaasen in East Frisia, who has managed to put two serial killers at work with completely unorthodox methods. He relies on her excellent feeling, a great honor for Kripochef Ubbo Heide. But when a young woman disappears from Leer without a trace and a gynecologist violently kidnapped, Ann-Kathrin is forced to act.
Without further ado, she decides to make an unusual self-experiment: her neighbor and long-time friend, the bricklayer Peter Grendel, is not even surprised when Ann-Kathrin asks him to wall her up. Her colleague and partner Frank Weller tries to talk her out of it, but she stays with it. After all, the criminal-scientific investigative methods have not yet taken them one step further. There is not much time left to put the puzzle pieces together in one picture, because on the third day without water, the life of the last two victims in their dark dungeon only hangs on a thread.