Macey arrives at the vaudeville theater and chats with the manager. As they chat, the ventriloquist, John Fabian arrives and the manager notes he takes it home every night. Fabian admits that he has nothing else to do if he loses his doll. After he leaves, Silver and Macey flip for a coin and drop it. It rolls down the stairs and when they go to get it, they find a corpse.
Later, Detective Krovitch shows up to investigate. He talks to Silver, who notes that the dead man, Ockham, visited the theater alter and came to see Fabian about becoming a ventriloquist. As Krovitch goes to see Fabian, he meets Mel Douglas, Fabian's agent. He tells the agent to stay for later and then goes to Fabian's dressing room and talks to the ventriloquist and his assistant, his wife Alice Fabian. Both of them claim not to know Ockham, and Krovitch points out that Silver said that the doorman claimed Ockham was inquiring about him. Fabian insists he doesn't remember. As they talk, a voice emerges from the nearby trunk. Fabian explains that his dummy, Riabouchinska, wants to talk. Krovitch thinks it's a joke but opens the case. Inside is a female ventriloquist dummy. Fabian describes her as irresistible, but Riabouchinska tells him not to boast about her when Alice is there. When Fabian tries to put her back in, Riabouchinska says that Fabian is a liar and she'll need to be present to get at the truth. Alice snaps at the dummy but Riabouchinska suggests that they bring in Douglas.
Fabian goes out to get Douglas while Alice explains that she soon discovered that her husband is more interested in Riabouchinska than in her. She admits that she's jealous of the doll, and explains that Fabian has spent more money on the dummy's dresses than her. Douglas comes in and denies that he knew Ockham. Krovitch asks if Douglas is involved with Alice, and Alice freely admits that she's having an affair with the agent. Krovitch figures that Ockham tried to blackmail them with the knowledge, but Fabian admits he knew about the affair. When he laughs, Riabouchinska tells him not to laugh.
Later, Fabian is performing with Riabouchinska, who says she loves him. Krovitch is watching, and a stagehand notes that Riabouchinska is a better dummy than Fabian's previous act, Sweet William. Afterward, Krovitch goes to Fabian's room and hears him talking about his love for Riabouchinska with the dummy. Fabian claims he's rehearsing and says that they're performing next week, but Riabouchinska accuses him of lying, Krovitch shows Fabian a photo of Ilyana Riamonova, who disappeared years ago. The detective checked the files and discovered that she was Fabian's assistant before he married Alice. He asks for the whole story and Fabian claims that he used Ilyana as a model. Krovitch doesn't believe it and forces Fabian to explain that Ilyana showed up and wanted to be an assistant. He took her on and fell in love, and then became jealous of her when she refused his advances. Fabian slapped her and claims Ilyana left. Krovitch reveals that Alice told him that Fabian took out articles to find Ilyana and hired a private detective. He never found Ilyana, but decided to do away with Sweet William. Fabian bought new wood and carved Riabouchinska. After months of effort, Fabian describes that Riabouchinska came alive, breathing and moving, and whispered to him that she loved him. Krovitch figures it's all an act, but Fabian insists that he loved Ilyana and wouldn't have killed her. He still claims he doesn't know Ockham, and Krovitch leaves in disgust.
Krovitch finds an agent, Zander, who dealt with Ockham, a juggler. Zander was unable to give him any work. He left a press book there and gives it to Krovitch. Krovitch goes back to Fabian and accuses him of lying. He shows Fabian one of Ockham's press clippings, which shows he was on the same bill with Fabian in Chicago. Fabian admits that he knew the dead man but it didn't mean anything. Riabouchinska speaks up and Krovitch tells Fabian to make the dummy talk. The dummy explains that Ockham remembered there was a woman before there was a dummy. She was there when Ockham came, and listened from her box as he argued with Fabian about money. There was a struggle and Ockham hit his head, and then Fabian dragged Ockham down the stairs to the basement. However, Riabouchinska explains that Fabian only killed Ockham, not Ilyana. Fabian finally breaks and says that Ockham threatened to hold up his love of Riabouchinska to the world and revealed them as freaks.
Riabouchinska says that they can't go along, and Fabian has refused to listen to her. She can live with Fabian's lies, but not his murderous ways. She closes her eyes and dies, as Fabian calls out in horror. Fabian drops the now lifeless doll to the ground as Krovitch takes him away.