The director of a large chemical plant Konstantinov decides to exploit the installations without the filters. The young engineer Stamatov is against this. The desire of the director is to fire Stamatov and put his colleague and friend Slavi at his place. Konstantinov leaves for Sofia with Slavi to discus all this with a leader of the committee. There is one free day until the meeting with him. Slavi meets his friends from the college. Gradually he reaches the decision to back the director up.