Trois de la Marine plot
Antonin, Honoré and Papillote are three marines on the ship "The Invincible". They are all in love with beautiful girls from Toulon: Honoré with Mireille, who loves Antonin herself, and Papillote has eyes only for Angèle, who tells him after fifteen months that her newborn baby is his son. A new woman shows up in their lives: Patricia, a mysterious, very attractive beauty. Antonin falls for her. Patricia claims to be a journalist, but in reality she is a secret agent, who has to shadow Eric Bergen, a man the three meet every day at a cafe.