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.
| Name | Type | Role | |
|---|---|---|---|
| William Corlett | Writer | ||
| John Golightly | Guest Star | Commanding Officer | |
| Eileen Davies | Guest Star | Nurse | |
| Paul Williamson | Guest Star | Mr. Carslake | |
| John Wheatley | Guest Star | Barton | |
| Nicholas Clay | Guest Star | Matthew Armitage | |
| Elisabeth Benson | Guest Star | Mrs. Armitage | |
| Elspet Gray | Guest Star | Mrs. Carslake | |
| Brian Anthony | Guest Star | Charles Crawley | |
| Emma Pierson | Guest Star | Sylvia Carslake | |
| Sarah-Jane Bickerton | Guest Star | Lucy Jerrard | |
| Nicholas Le Prevost | Guest Star | Derek Wainwright | |
| Kenneth Midwood | Guest Star | Mr. Hobbs | |
| Shaun Scott | Guest Star | Neil Carslake | |
| David Cook | Guest Star | Captain Mountjoy | |
| Valerie Lush | Guest Star | Mrs. Hobbs | |
| Jonathon Morris | Guest Star | Alan Carslake | |
| Agatha Christie | Director | ||
| Desmond Davis | Director |