Scared to Death

In the Central City morgue, two autopsy surgeons examine the unmarked body of a female corpse and contemplate what could have killed her: Laura Van Ee is trapped in a loveless marriage to her husband Ward, who married her one night on a drunken dare. After receiving mysterious, threatening letters from Europe, Laura begins to believe that Ward and his father Joseph, a doctor whose specialty is mental illness, are trying to drive her insane and, as revenge, refuses to grant Ward a divorce. One day, Dr. Van Ee receives a visit from a woman reporter, who is acting on a tip that strange things have been happening at the house.

Later, the doctor's cousin Leonide, a professor of magic, visits after an absence of twenty years, with his companion, a deaf-mute midget named Indigo. Leo was an inmate at the house when it was an institution for the insane, and after constructing countless secret passageways, he escaped and traveled to Europe. Ward now asks Leo's help in solving Laura's dilemma, and shows him a photograph that he found in Laura's room of a pair of Parisian dancers named Rene and Laurette, who are wearing green masks. The next morning, the maid, Lilybeth, delivers a package to Laura that contains a decapitated mannequin head painted to look like her, along with a message to "beware the man in the green mask." Later the doctor is knocked out while trying to call the police, and is discovered laid out on his desk with a sheet over him by a reporter named Terry Lee, his flighty fiancée Jane and house detective Bill Raymond. As Laura pleads for help from Terry, claiming that the Van Ees are holding her under house arrest, Lilybeth enters in a trance and, before collapsing, attempts to place a green blindfold over Laura's eyes. She is assumed dead and her body is placed in the doctor's basement laboratory.

The incident causes Laura to lapse into unconsciousness, and while she is thought to be sedated, gunshots are heard in her room, and the dummy head wearing a green mask is put in her place in bed. Leo, meanwhile, removes Lilybeth's body from the laboratory, and she is seen at the front door by Raymond, who loves her. The doctor explains that she is merely in a hypnotic spell, and Leo later revives her. Jane then reports that Laura shouted to a green face in her room that she "didn't mean to do it," before firing three shots and disappearing. Laura now screams, and is found transfixed in the living room. The voice of Rene, her ex-dance partner, coaxes Laura into admitting that they were once married. He was suspected of being a spy, and she took money from the Nazis to turn him in. She then sent him a green scarf of hers to wear at his execution so that he would know it was she who betrayed him. He was good and kind, she says, but she resented the power he had over her.

A practiced escape artist, Rene avoided execution, and now has returned for revenge. Just then, a figure in a green mask approaches from outside a window, causing Laura to scream before falling dead from fear. Outside, Raymond discovers Mrs. Williams, who is really Rene in disguise. Leo then reveals that Rene was his assistant in his magic act. They later met in a European concentration camp, and Leo returned to the Van Ee house to help him. Back in the present at the morgue, Terry and Raymond ask the autopsy surgeon what killed Laura, and he reports that she was literally "scared to death."