Frederick Loren, an eccentric millionaire, invites five people to a party he is throwing for his fourth wife, Annabelle, in an allegedly haunted house he has rented. He promises to give each guest $10,000 with the stipulation that they stay the entire night in the house after the doors are locked at midnight, all the windows are barred, and there are no phones or radios to use. The guests are test pilot Lance Schroeder, newspaper columnist Ruth Bridges, psychiatrist Dr. David Trent, who specializes in hysteria, Nora Manning, who works for one of Loren's companies, and the house's owner, Watson Pritchard. All are strangers to both the Lorens and each other, their only commonality being their lust for money.