 In New York, Dorothy Wynant visits her father, the inventor Clyde Wynant, with her fiancé to tell him that she is going to get married. Before traveling, her father opens the safe in his company to get some stock certificates to give as a wedding gift and realizes that his mistress Julia Wolf has stolen them. When Clyde vanishes and Julia is killed, his daughter approaches the former detective Nick Charles to investigate the mysterious disappearance. His wealthy wife Nora Charles convinces the reluctant Nick to work on the case, since it would be exciting for their boring life. When two other men are killed and Clyde is accused of murder, Nick invites all the suspects to have dinner with Nora and him and resolves the case, disclosing the real criminal.