Ellery Queen and the Murder Ring

Mrs. Augusta Stack, the irascible benefactor of the Stack Memorial Hospital, asks police Inspector Queen to investigate the hospital's medical director, Dr. Janney. Inspector Queen asks his son Ellery, an amateur sleuth and detective fiction writer, to look into the case, so Ellery feigns throat trouble and is admitted to the hospital as a patient. Ellery then sends for his secretary, Nikki Porter, to serve as his nurse. While out driving one day, Mrs. Stack is forced off the road by Bill Page and Lew Thomas, two criminals who have been hired by her son John to kill her. When her car is overturned in the accident, an ambulance is sent to take her to the hospital. Soon after, the car driven by Page and Thomas is involved in an accident, and Page suffers a broken leg in the crash and is brought to Stack Memorial Hospital in the same ambulance that is conveying Mrs. Stack there. At the hospital, Mrs. Stack is rushed into surgery, and after she is wheeled into the operating room, her lawyer informs Dr. Janney that she is claiming ownership of his latest medical discovery. Mrs. Stack dies shortly after her operation, but when Inspector Queen discovers that the cause of death was strangulation and not natural causes, he launches an investigation. Among those to be questioned are Miss Fox, the nurse on duty, and Page. When the inspector sends Sgt. Velie to interrogate Page, Page pretends to be asleep and then knocks Velie unconscious. Thomas then enters the room wheeling a gurney and begins to push Page down the corridor. After Thomas, disguised as a nurse, is recognized by the inspector, he flees into Ellery's room, climbs through a window and is later apprehended. Page, left stranded on the gurney, is mistaken by the hospital staff as an operating room case and wheeled into the wome's ward, where his presence causes an uproar. After propelling himself out of the ward, Page encounters Nikki and forces her to roll him into the supply room. Soon after, attendants from the morgue enter the supply room looking for Mrs. Stack's body. When Page pulls a sheet over his head, they mistake him for Mrs. Stack and deliver him to the morgue where the coroner turns him over to the police. Meanwhile, Ellery has checked out of the hospital and goes to question Miss Fox. At her apartment, he finds her dead body, the apparent victim of suicide by hanging. Soon after, some criminal friends of Page come to the hospital to help him escape. Mistaking Mrs. Stack's covered body for that of Page, they wheel it out of the hospital and to their hideout. Two friendly police officers help them carry the body up the stairs, but when the officers discover they are transporting a corpse, they arrrest the criminals. That night, in the park, John meets Miss Tracy, the head nurse at the hospital with whom he is in love. Miss Tracy, who is more interested in the Stack millions than in John, informs him that his mother has willed the bulk of her estate to the hospital. She also tells John that the morgue officials have turned Page over to the police. When she sees his reaction, she realizes that he was involved in his mother's murder and leaves, seemingly horrified. Meanwhile, at police headquarters, Page and Thomas implicate John in his mother's murder. Soon after, John is found dead and Nikki becomes suspicious of Miss Tracy and goes to question her. When Nikki accuses her of murder, the nurse attacks her. At police headquarters, meanwhile, Ellery deduces that Miss Tracy murdered Miss Fox after the nurse witnessed her suffocate Mrs. Stack, and upon learning that John had been disinherited, she drove him to commit suicide. Ellery, accompanied by his father, then rushes to Miss Tracy's apartment, arriving just in time to overpower Miss Tracy and save Nikki.