John Harrison

In the short story Wasps' Nest, John Harrison was a friend of Hercule Poirot and one of two men in a love triangle involving Claude Langton and Molly Deane. Poirot intervenes before there is a killing among them. The barebones plot of the story gives very few details about Harrison beyond the fact that he was suffering from a terminal illness.

Portrayals
John Harrison was played by Martin Turner in the film adaptation of Wasps' Nest in Series 3 of ITV's Agatha Christie's Poirot drama series. Here the character is considerably embellished for dramatic purposes. John becomes the son of one of Poirot's oldest and dearest friends in England. John is a philosopher and has written three books, two of which were "Dualism and Determinism, an Exploration of Classical Platonic Philosophy" and "Aristotelian Ethics, A Short Guide to the Metaphysical Works of Aristotle".