A magician uses hypnosis to create an army of murderers.
A rather silly but engaging film noir. Fingers at the Window is the tale of a sweet but rather dumb girl, played by Laraine Day, who is being targeted by ‘maniacs’–several of whom have murdered seemingly random citizens– whom the authorities, influenced by the police psychologist who scoffs at ‘mastermind’ conspiracy theories of crimes and criminals, assume have no connection to one another and are simply a collection of lunatics copying each other. Her hero, played by Lew Ayers, finds the connection between the crimes in the form of the urbane, insane Basil Rathbone, the mastermind who has taken on another man’s identity and is hypnotizing hapless, mentally ill minions to do his killing for him. Due to his meddling, our hero is eventually blamed for the crimes but of course everything turns out fine in the end.
About Lew Ayers, from here
: MGM's mystery-thriller Fingers at the Window (1942) stars Lew Ayres as a young Chicagoan who suspects that a series of ax murders in his city are being committed by people under the spell of an evil hypnotist. This was Ayres' last film until the end of World War II since he announced that he was a conscientious objector - an event that sent shock waves through his home studio, MGM, where Ayres had established himself as a sensitive young actor in the Dr. Kildare series. Public outrage, at a time when other film stars including MGM "King" Clark Gable were heading off to war, meant that Ayres' acting opportunities vanished. Exhibitors refused to show his films, and they were withdrawn from circulation. Some felt that his pacifist leanings could be traced to his greatest role, the disillusioned young German soldier in Lewis Milestone's anti-war All Quiet on the Western Front (1930).
Ayres, well cast as a doctor because of early medical training, volunteered for non-combatant duties during the war, working as a medic and distinguishing himself under fire. He later served as a chaplain's aide. Partly appeased, the public accepted him in films again after the end of the war. He claimed a few good roles and was nominated for a Best Actor Oscar for his role as a kindly doctor in Johnny Belinda (1948); but old resentments seemed to die hard, and much of his work until his death in 1996 was in minor film and TV productions.