A pair of photographs are the only clues that Poirot has to solve the murder of a village charwoman, and to prove the innocence of the victim's lodger.
A foreign revolution, a kidnapped princess, and a trove of priceless rubies are linked to a prestigious girls' school, where staff members are brutally murdered.
After a seemingly neurotic young heiress tells Ariadne Oliver and Poirot that she thinks she may have killed someone, her ex-nanny is found with her wrists slashed.
