A cunning jewel thief has been giving Scotland Yard Inspector Grey a hard time for a long time. Nobody suspects that the man keeping the police on their toes is the likeable Roger Edgeston, the son of the Duke of the same name. When the shrewd crook meets the enchanting Jennifer Lindsey on a cozy summer night, fate takes its course, as the charming young lady also engages in criminal activities in her spare time and acts as a blackmailer. In the course of the evening, the duke's son is forced to...