Inspector Max Ballauf has to look after the house and daughter of his beautiful cousin Beatrice for a few days - the former soft porn actress goes to the hospital for a cancer test. Just now, Ballauf is being threatened by a stranger over the phone – and a woman with whom he had a one-night stand years ago is brutally murdered. The perpetrator leaves a red lily at the crime scene. Ballauf and Schenk are groping in the dark - apparently something is to be avenged, for which the stranger blames Max. But as much as the two examine old cases and look for a needle in a haystack, they find no plausible trace into the past. The only thing that is clear is that it is a revenge campaign against Max. When the stranger kidnaps another of Max's ex-girlfriends, a race against time begins.
He chases the detective halfway across town with a ransom of €300,000 – only to get him to publicly burn the money. Max can't prevent the death of this ex-girlfriend either. The only clues left by the unsub beside the flowers are a cryptic crossword and the poison used to kill the victims -- it comes from the lab where it's being studied, of all things. But when, despite all security measures, little Anna is kidnapped, Ballauf seems to be facing the biggest defeat of his life...