Caldicott stumbles upon the body of a woman stabbed to death in his bedroom. She is named as Jennifer Beavers, who the pair knew as a child. When Jenny contacts them it appears this woman was killed by mistake.
Charters is held at gun point by a man wanting to view Colonel Beavers trunk. He lets him go so to give away Jenny's cover. Venables arrives at Jock Beaves funeral claiming to be the official mourner. Charters and Caldicott are suspicious.
Margaret gets Charters and Caldicott invited to a country house party mixing with many familiar faces. Chauffeur Gregory wants to know who murdered his wife Helen Appleyard which gets them wondering whether Jenny is a fraud.
Chauffeur Gregory has been murdered. Jenny is on the run with Insp. Snow discovering the deception. Venables admits that Col. Beavers was a smuggler. Rev. Lamb has a box of documents that could lead to stolen gold bullion.
Charters and Caldicott try to break the code that leads to the U Boat and gold bullion. They discover that Gordon Wrigley went to Hong Kong and murdered Col. Beavers. He is now working with accomplice Meg who was their Jenny.
With the real Jenny Beavers in New York, a scheme has been hatched by Meg (fake Jenny) to save her father's business with the money from the Will. Wrigley, however, plans to keep the money himself but needs Charters diary first.
