Six months after the body of Evelyn Maxwell, who was the assistant to the magician Azrah, is pulled out of a river, the detective assigned to the case, Jed Dobson, is still searching for clues. When he visits Azrah, whom he knew years before on Coney Island, the magician is conducting a seance for Mr. Russell and his daughter Constance. When Constance's fiance, David Adams, arrives at Azrah's house, Azrah's partner, Albert Young, will not let him in, so David enters through an open window. When he finds Azrah, David says that he suspects him of killing Evelyn and produces an envelope containing canceled checks from Azrah to Evelyn. With the help of his trick electrician, Metzger, Azrah creates an illusion that keeps David from confronting him any further. Young comes in and picks a fight with David, so that he can steal the canceled checks. Jed then enters, but before he can question Azrah, La Tour, whom Evelyn had assisted prior to Azrah, arrives. Jed questions La Tour about Evelyn, but he says he knows nothing. Azrah overhears this and suggests that he conduct a seance that evening to get a confession from Evelyn's spirit. La Tour has his two henchmen, a hunchback and a Chinese man, kidnap Constance so that he can give Young money to sabotage Azrah's seance when the others go to rescue Constance. At the seance, after the guests are forced to relinquish their weapons, Azrah is tied to his chair to ensure that he does not leave when the lights go down. After the lights flash on and off, La Tour is found dead in Azrah's chair with a penknife through his heart. The knife belongs to Evelyn's father, who is disguised as a guest, Professor King. Azrah asks to continue with the seance and, with the help of his assistant Maisie Henry, tricks everyone with an illusion, using sound recordings of a conversation he had with Evelyn before her death. In the recordings, she confides that La Tour, who would not marry her, left her pregnant and penniless, and that she was then unable to return to her family. Evelyn's father, who was trying to kill Azrah because he thought that he was responsible for Evelyn's death, confesses to La Tour's murder, and he is arrested. Azrah goes on to explain that he knew all along that La Tour had killed Evelyn because he had originally sent the canceled checks to La Tour knowing that he would have returned them to Azrah to protect him if he was innocent. Azrah reveals that La Tour, however, sent the checks to David in order to frame Azrah. Azrah then orders David to pay more attention to Constance, and the young couple embrace.