While street photographers Máček and Kalabis are vainly offering their services to passersby, a pair of cronies rob a jewelry store almost right in front of their eyes. Kalabis accidentally manages to photograph one of the robbers. Coincidentally, the brutal thug is indistinguishable from the notorious bookseller Karel Pelikán. Hard times await him: the police, led by the experienced district inspector Moudřý, are interested in him, as well as a gang of criminals who accidentally slipped Karl a ticket from the train station locker where they hid the loot. The only ones who trust Karl are his good-natured aunt Klára and his girlfriend in love, Jarmila...