On their way to a boxing competition in Buenos Aires, the criminal investigator Harry Winkler from Berlin and Conny Steven of Scotland Yard, meet in Lisbon. Both have a 90 minute break before their ship leaves for South America. They end up meeting Ilse Siebeck, a young woman and through her become part of a criminal mystery. Ilse's uncle is murdered and Harry Winkler is quickly able to determine that the man who murdered her uncle is the exact same man who murdered his father a few years earlier.