The student Hans Kessler is suspected of having murdered the banker Hergotin, who has been found dead in his hotel in Zurich. When a search is launched for an unknown woman, who was seen in the hotel at the time of the murder, Hans suddenly confesses to the deed. The prosecution is headed by Schweda and Hans is sentenced to fifteen years in prison. Only afterwards does Regine, Hans' sister, find out about the events. She is convinced that her brother is innocent and is covering for the actual murderer.