Michael Kühnert, who runs a sailing school, discovers a body in the water. It’s the body of a former officer of the Dutch KFOR troops in Kosovo who has been stabbed to death. Lead detective Jan Holzer finds out the victim’s identity from a group of deaf sailors, with Kühnert interpreting since his wife, Elena, is also deaf. Jan Holzer is fascinated by the “mute communication”, but especially by Elena. Kühnert, himself a former special forces soldier who served in Kosovo, where he met Elena, claims he didn’t know the dead man. But Holzer senses that the couple are hiding something. While Holzer – plagued by his own feelings of guilt – delves ever deeper into the family’s secret, his assistant Amal Catack researches the murder victim’s past, and discovers a terrible crime.