Thriller - Season 1 (1973)

An American visiting London becomes confused about the facts of his life, particularly those related to a mysterious Theresa.

A serial killer escapes from the asylum to which he has been confined. He picks a seemingly innocent woman as his next victim, but soon it looks like she's not quite as innocent as he thought.

While suffering from amnesia, Betty Drew stumbles into a police station; unable to identify herself but admitting to having just committed murder. Her elaborate, yet muddled, story is dismissed when no body is found. Her claims are explained as being the result of a concussion and repeating plots from her writer husband's mystery novels. However, one police detective, Tom Patterson, wants to investigate further.

Doctor Bruce Nelson takes over the medical practice of a village general-practitioner. Upon arriving in their new home, the doctor and his wife, Tessa, receive a very warm welcome from all the villagers. Tessa is at first flattered by the villagers' constant fawning and gifts, but soon becomes wary of their strange ways, and begins to suspect there is something evil in the village.

A strangler is on the loose, killing young women, and there are several suspects. Liz Morris, the local librarian, is the only person who can provide clues.

A group of terrorists posing as plumbers set up base at a school for the blind. The students remain blissfully unaware, while the terrorists plan the assassination of a politician who will soon be passing the school on a parade route. Only one student, Sally, suspects that the men upstairs may be dangerous...

Businessman Tony Mansell hires a marriage bureau when his wife dies from a sudden illness, and is delighted to find himself paired up with the beautiful Clara. Despite seeming like the perfect wife, Clara is in fact a witch and has nothing but evil intentions for her new husband. She soon envelops her grip around Tony and he begins to fall sick from the same illness that had killed his wife...