Three Act Tragedy

A cocktail party at the house of Sir Charles Cartwright, a famous actor, seems an unlikely place for murder. A vicar chokes on his drink and dies in front of everyone, and Poirot, who is among the guests, reads it as a tragedy. Old men choke. These things happen. Then another guest dies in exactly the same way, and accident stops being a word anyone can use with a straight face.

The party has the sort of guest list Christie loved: Sir Bartholomew Strange, Miss Milray, Egg, Cynthia and Captain Dacres, Lady Mary, Mrs Babbington and Miss Wills, who noticed more than she lets on. Poirot goes back over the evening, and over every account of it, while the wealthy circle that hosted it closes ranks. Nobody wants to believe the first death was murder. The second one makes that position untenable.

Nick Dear wrote the adaptation with Christie, and Ashley Pearce directed. Martin Shaw is excellent as Sir Charles, with Kimberley Nixon as Egg, Art Malik as Sir Bartholomew Strange, Suzanne Bertish as Miss Milray, Anastasia Hille as Cynthia Dacres, Ronan Vibert as Captain Dacres, Kate Ashfield as Miss Wills, Jane Asher as Lady Mary and Anna Carteret as Mrs Babbington. It aired at the start of 2010, a New Year treat.

The title turns out to be the joke: a tragedy in three acts, with each death as an act. But what impresses is the method, killing a man in a room full of witnesses without anyone seeing a thing. It is the kind of audacity that only works in a Christie, and the episode earns it.

Poirot has done his best work in drawing-rooms, and this is one of the purest examples: a single evening, a fixed group of people, a killer who had to be clever and got away with it for exactly as long as the structure of the evening allowed. The solution, when it comes, is a proper shock.