Julien works in an office and lives with his invalid mother and his girlfriend in a pre-war Paris apartment. He feels like the two women take advantage of him and at night, he dreams of sex and violence. Meanwhile, a murderer is loose in Paris, killing women. One day in the metro, Julien believes he sees a murder victim from his dreams; the enigmatic beauty leads him into an old shopping arcade peopled by strange figures, where he meets prostitute Bichette. The independent, confident young woman starts an affair with the clerk. But then Julien witnesses a real murder in the glass-roofed arcade….