Semyon Gorbunkov goes on a cruise. In Istanbul he slips and breaks his arm. What he didn't know is that this was a signal for a gang of smugglers (a real smuggler - Gena - was also on board the same ship). So his arm gets bandaged with gold and diamonds. After he returns home the gangsters are trying to get their stuff back while the police try to catch them using Gorbunkov and his arm.