Alois, Wendelin, Schani and Franz operate an auto repair shop in Vienna. One evening, Alois fishes the suicidal Hannerl out of the Danube and takes her to live with him. The timid and taciturn woman soon disappears however, and with her, a large amount of cash out of the shop's cash register. A disappointed Alois wishes to forget about her, but his three friends look for Hannerl and the money. As it turns out, she's married to the smuggler Kerrylis, who forces her to take part in his business; that's why she tried to kill herself. When Kerrylis is found dead, Alois is suspected of being the murderer.