Appointment with Death: Agatha Christie

A repugnant Amercian widow is killed during a trip to Petra...
Among the towering red cliffs of Petra, like some monstrous swollen Buddha, sat the corpse of Mrs Boynton. A tiny puncture mark on her wrist was the only sign of the fatal injection that had killed her.
With only 24 hours available to solve the mystery, Hercule Poirot recalled a chance remark he`d overheard back in Jerusalem: `You see, don`t you, that she`s got to be killed?` Mrs Boynton was, indeed, the most detestable woman he`d ever met...