When a vicar chokes to death on a cocktail while attending a party held by actor Sir Charles Cartwright, Poirot initially dismisses the idea of murder but reconsiders when another guest dies in the same manner.
Poirot (Hercule Poirot) is asked to assist in a murder investigation to determine if a young woman is responsible for the crime. But mounting complications in the case, including multiple frozen clocks, lead the detective to suspect an international political cover-up.
Ariadne Oliver (Zoe Wanamaker, Harry Potter) returns to join forces with Poirot to investigate a drowning at a Hallowe'en Party. As they look further, they uncover a series of mysterious deaths in the village. Are they connected? Adapted by Mark Gatiss (Sherlock).