In the past, Sergey Rashidov was a successful surgeon who, by coincidence, had to radically change his profession and even his name. Now he is Djura's janitor, forced to live on forged documents. During the morning cleaning, he finds a wounded bandit named Conrad. Filled with medical duty, Rashidov provides him with first aid, and then secretly treats him in his janitor's room. Major Alyoshin, an employee of the homicide department, becomes aware of the circumstances of the shooting, and Konrad's rival, the leader of a criminal group, the owner of a nightclub nicknamed Lucky, finds out where Konrad himself is. Fearing revenge, Lucky decides to blow up a competitor's car and find and punish the doctor who helped Conrad.