A killer of young women, referred to as Bluebeard, is loose in the streets of Paris. Lucille and her friends meet Gaston Morrell, a puppeteer. He invites them to a show the next night. Afterwards, while Gaston and Lucille walk together, she offers to make costumes for his next show and he accepts. Soon, feelings develop between the two that may lead to love. Meanwhile, his leaving the show with Lucille makes Gaston's sometime lover, Renee, very jealous. Lucille's younger sister, Francine, returns to Paris with her boyfriend who is Inspector Lefebre and who is hunting Bluebeard. Some clues point toward Lamart, a greedy art dealer. But it is unclear who is in danger and whether or not Gaston can be trusted.