Mr Pelham is a pattern of respectability. His firm is solid and high-class, his club impeccable and his history blameless. But one day uneasiness, which grows quickly to alarm, seizes him. It appears that he has a double, who begins to interfere in his life. He is driven to cunning and frantic schemes to outwit his strange enemy, and the suspense builds up inexorably to a climax which is handled with Anthony Armstrong's customary skill.