When Sister Rose receives an anonymous letter pushed through her door at St. Beade's Home for Retired Nuns in Ormskirk warning her that somebody at Lady Entwistle's dinner is going to die, she is surprised and shocked. Not as surprised and shocked as when she meets Helen McGowan who she knew during the war, and whom she helped shelter from the Nazi's by disguising her as a nun at the Vatican. Discovering that her friend is now a serving Police Officer she invites Inspector McGowan to Lady Entwistle's dinner to discuss old times and see to it that no harm comes to any of the other dinner guests. But, soon, death strikes.