Tommy and Tuppence are restless for the excitement of their early careers. When Mr Carter, Chief of Intelligence, asks them to take over Blunt’s International Detective Agency, they leap at the chance. To guarantee they can live up to their slogan, ‘Any case solved in 24 hours’, they decide to emulate the great historical detectives. After their triumphant recovery of a pink pearl, intriguing cases keep coming their way: a stabbing on Sunningdale golf course; cryptic messages in the personal columns; and even a box of poisoned chocolates…