At a party thrown at the Metcalf estate, the Marquise D'Irancy's Sultana diamond disappears when the lights go out during a power failure. Suspected of the crime is William Kirkland, the wastrel son of the wealthy Kirkland family, but William's sister Diana comes to his defense. Aiding her in the investigation is Clamp, a wandering peddler.

Cast

Frank Mayo

Clamp

Ora Carew

Diana

Harold Miller

James Kirkland

Dagmar Godowsky

Patricia Melton

Bonnie Hill

Marquise d'Irancy

Ora Devereaux

Leontine de Vallignac