England, 1925. After years shut away from the world, former detective Lord Edgington of Cranley Hall plans a grand ball to celebrate his seventy-fifth birthday.
But when someone starts bumping off members of his scheming family, the old man enlists his teenage grandson to help find the killer, before one of them is next.
The mismatched duo must pick the culprit from a gaggle of preening playboys, scatter-brained spinsters and irate inspectors in this Agatha-Christie-style whodunnit that will have you racing to spot the killer.