Sven Haasberger is swimming coach with body and soul. His boys love him and also the representatives of politics have positively noticed the honorary commitment of the 40-year-old. When Haasberger receives a check for his club at a public event, the square suddenly fills with a horde of hooded figures. In a scuffle Haasberger goes down badly injured, the emergency doctor gives him hardly a chance from the beginning. Chief Inspector Jens Stellbrink and his team are faced with a mystery. But smearings quickly point to a possible motive. The trainer is accused of having abused his protégés. Haasberger seems to have been particularly active on the Internet to address children under a pseudonym. The flash mob therefore seems to be a form of lynch law. But while the case is clear to outraged parents and the public, Stellbrink has doubts...