The film centers around an orphan youngster who works as cleaner in the Ministry of Internal Affairs. Working in the cellar of the ministry he learns about the criminal activities of governemtn agents. Even high-ranking civil servants collaborate with the fascists for their own benefit. The boy wins the confidence of the officials and secretly collects information on the events. He forges keys and eventually manages to enters the secret archive of the ministry. With this knowledge he turn to the Antifascist National Liberation Movement and helps the comrades who work undercover to seize the secret archive.