Last in the long-running series featuring amateur detective Dr Launcelot Priestley.

Freddie Hapton, a young testpilot, finds himself one winter's day making a forced landing by parachute amid the snow-covered hills of Benshire. Spending the night in a deserted shepherds' hut, he notices a green metal box secured by two padlocks. The significance of this box in the affairs of the nearby Greystoke family becomes the problem that Superintendent Jimmy Waghorn has to unravel when one of them is murdered mysteriously. How did it fit in with the theft of the silver bust of the Empress Eugenie that was an heirloom of the elder branch of the Greystoke family? Jimmy, in between visits to the North Country, is helped by a few hints from his friend Dr. Priestley.