Gennarino Laganà is a poor Sicilian who struggles with menial jobs to support his family, while his parents pressure him to seek his fortune in the North. Gennarino would never leave his beloved island if he had not stumbled into a love affair with Donna Egeria, wife of the Mafia boss Don Mimì. To escape certain revenge, he boards a goods train. In a dream, Saint Totino appears to him and promises him protection in exchange for a regulated life. He thus arrives in Milan, where he meets Armida, a woman of the streets, who takes him into her home and makes him her protector and lover. But San Totino appears again to Gennarino and reproaches him for being a kept man: he must work and Armida must change her life.