Albert is an eccentric inventor of missiles who comes under fire from his investors when his first prototype explodes. Even his sympathetic mistress has her doubts, as Albert lashes out in a verbal tirade condemning those of little faith in his genius.
A group of policemen look over three murder cases including a cutthroat that prays on young women, a madman that hid his deformed landlord's corpse in the floor, and a wine aficionado who buries his friend alive.
Returning by train to the French port of Le Havre, Jacques Lantier, a tormented railwayman, meets by chance the impulsive stationmaster Roubard and Séverine, his wife.