The Agatha Christie Hour. Episode Two - In a Glass Darkly

Tales of romance and danger in the glittering 1920s and ’30s
How can “happiness expert” Parker Pyne return a wayward husband’s affections to his wife? Will a chance encounter on a train transform the life of a jobless investment broker forever? And why does a vision in a mirror mean misery for a beautiful bride-to-be?
In these stories, lesser-known Christie heroes and heroines solve crimes of the heart as well as puzzling cases of larceny and murder. With just the right mix of danger and deception, romance and revenge, innocence and intrigue, these classic adaptations are Christie at her best.

In a Glass Darkly.
While visiting Badgeworthy, the home of the Carslake family, Matthew Armitage experiences a strange and frightening vision in a mirror in his bedroom of a man with a scar strangling Sylvia Carslake.
Time passes, the First World War takes place, and then finally Matthew marries Sylvia Carslake. However, suffering badly from shell-shock, he nearly destroys his own marriage through an Othello-like jealousy and possessiveness which threatens to destroy both him and Sylvia, until one night Matthew's vision of the man with the scar comes back to haunt him.