Bobby Carson is proud of his lying expertise. His scientist father uses him as a guinea pig for a machine which destroys his ability to be dishonest, but has unhappy social consequences. Soon criminals begin exploiting the possibilities of a world without lies in a society built upon sham and pretence. And Scotland Yard, hampered by its own guilty secrets, cannot stem the tide of blackmail...until Dr. Carson, the creator of the Lie Destroyer, again steps into the scene...