In a hospital's five-bed room—room number 13—there are five very different men with very different backgrounds: District Court Judge Winther, fashion designer Philip André, bank teller Madsen, the incorrigible burglar Herluf "Smukke Arne" Jensen, and legation secretary Konrad Konradsen. The legation secretary has done something foolish and fallen into the clutches of the blackmailer Helmer Gamtofte. He is in possession of some compromising photographs, which he keeps in a safe deposit box at the bank where Madsen works. The camaraderie that develops in room 13 becomes the driving force that prompts the district court judge to suggest that "Smukke Arne" help Konradsen break into the bank and steal the photos.
