During demolition work in a village in northern Germany, a cemented-in corpse is discovered in the wall of a building. The autopsy leads the pathologist to conclude that the man suffocated in the cement. The identity of the dead man comes as a surprise to the two detectives on the scene: it is Michael Lehmann, who has been missing for 16 years. He was suspected of having sexually abused and murdered a nine-year-old boy from the village.