A petrol pump is run by a permanent team: the manager Vávra, a former civil engineer ing. Stejskal, a smug crook named Karafa, and an old man, Dvořák, who is about to retire. They have a well-developed system that allows them to divert part of the profits into their own pockets. The only one who wants nothing to do with the crooked business is old Dvorak, who one day will find another job. Into this situation comes a young man, Zdeněk Černý, as a new employee. He's inquisitive and works quickly. He also understands the profit-sharing system. He soon inspires confidence in Vávra and the others, but soon starts to assert his right to an equal share of the profits...