Pozdnycheff, a young party animal, destroyed by his lightness the marital happiness of one of his childhood friends who committed suicide. Since then, he is haunted by the memory.
In the village of Sableuse, the local manor has been bought out by a nouveau riche, Emile Cousinet. When his wife Lisette, a former music hall actress, flees to Paris with young Pierre de Sableuse, Cousinet asks Father Pellegrin, the village vicar, to bring the lost sheep back home.
Three mice run, cavort, sing and dance around in the stores and restaurants a big city at night. They wind up in a café for an early-morning snack and stocking up on food provisions before they return to the safety of their den beneath a man-hole cover in the street.
A cocky young Marine who's alienated many of his fellow soldiers with his smart-aleck, wiseguy attitude gets a "wake-up call" when his unit comes under attack by bandits.
The mangiest pup at Pete's Pooch Palace catches the Captain's eye. He takes it home, but Mama is less than thrilled; she forbids it to stay in the house.