Cole King's variety troupe, along with press agent Rick Daniels, and Mrs. Thorn, the wardrobe mistress, occupy a Malibu, California beach house. When Adelaide, a showgirl, criticizes Marcia, the imperious star of the show and King's girl friend, Marcia threatens to reveal that Adelaide is secretly married to physician George Brandt and also hints that she knows Brandt's real identity. Marcia then forces showgirl Lois to steal letters from Adelaide's trunk by threatening to tell King that Lois is under eighteen. Later, Marcia disappears and Lois' body is discovered by Chinese troupe member San Toy. Because Lois has been strangled, a murder technique said to be favored by the Chinese and the French, both San Toy and Adelaide are under suspicion. When Daniels suggests that they try to make Lois' death appear to be a drowning, San Toy, who is a friend of Jimmy, the son of Chinese detective Charlie Chan, asks Chan to investigate. During the course of the investigation, both Chan's assistant Birmingham and San Toy are attacked. Later troupe member Clementine finds Marcia's body, a silk cord wrapped around her neck, washed up on the beach. Later, Chan discovers Daniels burying Marcia's bathrobe. When Chan reveals that the cord from the robe was used in one of the murders, Daniels claims that the robe was planted on King to frame him. Then King accuses Daniels of murdering the women and trying to hide the evidence. Privately, Chan reveals that he knows that Brandt was once accused of his wife's murder, and although he was exonerated, his career was ruined. He went to war and met and married Adelaide in Paris, where Marcia first met them. Brandt admits that he found Lois' body and removed the letters, but denies killing her. Chan then decides to set a trap for the killer. That night, King confesses that he took a box from Brandt's suitcase that contained incriminating papers. Jimmy later finds the missing box in the furnace. Jimmy then sees someone try to strangle San Toy and intervenes, inadvertently spoiling Chan's trap. Chan, Jimmy and Birmingham chase her attacker, who is revealed to be Mrs. Thorn. Mrs. Thorn had deserted King, her husband, and when she wanted to return to him, he humiliated her by offering her a job as his wardrobe mistress. She then killed the two women and framed King in order to make him suffer. Her letters were in the box that King stole from Brandt. Later, Chan assures Brandt that the Board of Medical Examiners will reinstate his license and he will be free to practice under his own name.