Bernardo Mambelli is a Milanese worker in a paint factory with a passion for boxing. He is nicknamed I l Gandi, and in addition to being a trade union activist, he is a convinced militant of the PCI. One night he saves the young Claudio from the aggression of some fascists. Since poor Claudio is wounded and in pain, Gandi takes him home without knowing that the boy is homosexual. As soon as he realizes his orientation, Gandi awkwardly seeks his friendship with Claudio from his girlfriend Maria and his party mates, but above all to Mrs. Elvira, the nosy and drunken concierge of the building. The concealment succeeds and Claudio, healed of his wounds, returns to his usual life, until the fascists take up the young boy again, setting the alternative bookstore where he works and lives on fire. Gandi then decides to host Claudio again, by now a place to stay, but without always hiding it from everyone so as not to compromise himself. In the evening they take advantage of the darkness to make the move, but everything is accidentally discovered by Maria, who confides in Walter, Gandi's colleague and best friend, to ask him for help.