Poirot - Season 13 (2013)

Ariadne Oliver becomes an amateur sleuth when her goddaughter tasks her to find out the truth behind her parents' mysterious deaths.

As the threat of world war looms large, Poirot seeks the help of friends both old and new when he is pitted against a dangerous group of dissidents responsible for a series of violent murders.

Mrs Oliver is asked to devise a murder hunt for a Devon fête, but her sense of foreboding summons Poirot to the scene. Her fears are realized when the girl playing murder victim winds up truly murdered.