Who Shot Otto Mueller?

After the murder Otto's youngest son Oliver, who was once a talented musician, is brought in for questioning; he tells a story, where unexpected visitors play a dramatic part.

Oskar, Otto's oldest son and former athlete, has long waited for some promises to be fulfilled, something that never happened; he finds his own way to cope.

Marleen, Otto's young mistress reveals some interesting facts from the past; she also has a gripping story about Otto and a weird tale about a bet; new details about Agnes's life really catch Gabriel's eye.

Merle, Otto's wife, a family therapist, shares her memories of young Otto and how it all started; Anneken's brutal habit becomes known to the detectives; Agnes finds out a new fact about Gabriel.

Anneken, Oskar's homemaker wife, brings unexpected new leads into the case; her personality makes them twist their heads; the relationship between the detectives takes a turn.

Monika, Oliver's seemingly carefree and charming wife, has recently got an expensive present from Otto, that has everybody turning their heads; time is running out and the stakes are getting higher.