No one from her flat-share has seen Ingrid Helberg for four days. Her friend Christa turns to a mutual friend – Gerd Heymann – for help. Ingrid never missed a date, at the very least would call if she was going to be late; in fact it was hard to imagine anyone more reliable. Since the police have no unidentified female corpse on record, Heymann and Köster pay her flat mates a purely friendly evening visit. First statements from co-sharer Jan suggest that Ingrid may simply have chosen to keep her head down for a bit. Since she has kept everyone in the dark about her job in a publishing house, Heymann sets out the next morning to find her employer. It soon transpires that Ingrid had been leading a – much more dangerous – second life.