A spiritualist tries to take an advantage of a bereaving woman; but an executed murderess takes over her body to get revenge on him.
Ruth Rogen (Vivienne Osborne) murdered three lovers and is sentenced to death. Dr. Carl Houston (H. B. Warner) asks the Warden (Willard Robertson) for her body to prevent similar crimes by the dead's spirit, and they persuade Ruth to consent. In a funeral parlor Paul Bavian (Alan Dinehart) makes a mask from John Courtney's corpse. Paul reads that Ruth swore revenge against the man responsible. Paul's landlady (Beryl Mercer) drinks and read's Ruth's letter asking Paul to come see her, then gives it to him. John's sister Roma Courtney (Carole Lombard) inherits his fortune and mourns. Nicky Hammond (William Farnum) advises Grant Wilson (Randolph Scott) to marry Roma, who gets a letter from spiritualist Paul that John wants to communicate with her. Hammond calls it fraud, but Dr. Houston says life goes on after death. Roma asks Grant to go with her.
The landlady calls Paul a fake and wants to be his partner, but he causes her to collapse. Paul and Roma ask Grant not to be hostile. After Paul goes into a trance, John appears to tell Roma that Hammond murdered him for their money. After they go, Paul removes John's mask and chuckles. Roma and Grant call on Dr. Houston, barge in and see Ruth. Houston warns Roma and Grant about contagion from Ruth. Grant says that Paul tricked Roma, but Houston advises her to have another séance. Houston says that Ruth tried to take Roma's body. In a séance at Roma's house Roma, Grant, Houston, and Hammond sit at a table while Paul plays piano until he faints. The same message is burned into the handkerchief Paul put on the lamp. Roma faints, and Ruth's spirit enters her. Hammond is found dead, and Roma leaves with Paul.
Roma takes Paul to Ruth's apartment. Paul admits he knew Ruth and kisses Roma. When Max comes in, Roma tries to strangle him; but Paul stops her. Paul suggests they go to her yacht, where Roma seduces him. Grant and Houston follow them, and Max says he found them in Ruth's apartment. Houston says only Ruth could have known and faints. A spirit guides Grant to the boat. Roma gets Paul drunk, and he fears Ruth. Roma strangles him and admits she is Ruth; but Grant breaks in to stop her. Ruth's spirit departs as Paul falls overboard with a rope and hangs himself. Grant revives Roma, who is now herself and does not remember. The spirit of John suggests they honeymoon.
This plausible horror story is based on the spiritualist understanding that the soul leaves the body at death and may possess other bodies that somehow allow this to occur. Dr. Houston's point that executed criminals may haunt others, causing more crimes, is another argument against capital punishment.