E1 - You Killed Toby Wren

Aired: December 14, 1970

Quist's authority is questioned from all directions, and Ridge does some quiet investigations into hybrid science in Norwich.

E2 - Invasion

Aired: December 21, 1970

Ridge and Hardcastle are sent on what seems a simple enough assignment, but stumble onto a major government cover up in an abandoned English manor.

E3 - The Islanders

Aired: January 04, 1971

Doomwatch become involved with the inhabitants of a small, secluded island who have been forced to leave for the English mainland and are struggling to survive.

E4 - No Room for Error

Aired: January 11, 1971

A deadly new strain of typhoid is sweeping through local schools. There is a treatment, though, and the team at Doomwatch endorse this in spite of its side effects.

E5 - By the Pricking of My Thumbs...

Aired: January 18, 1971

The Doomwatch team investigates the myth about the XYY chromosome after a schoolboy is expelled for possessing it.

E6 - The Iron Doctor

Aired: January 25, 1971

A computer oversees the wellbeing of patients at a local hospital. The Doomwatch team look into whether it is saving patients or if something more sinister is afoot.

E7 - Flight into Yesterday

Aired: February 01, 1971

After a long-haul flight Dr Quist's reputation is put seriously in doubt when he arrives drunk to a meeting with the Prime Minister. Is it a simple case of jet-lag, or sabotage?

E8 - The Web of Fear

Aired: February 08, 1971

The Doomwatch team investigate the mysterious outbreak of a deadly subtropical disease which somehow has cropped up on an isolated island off the coast of the UK.

E9 - In the Dark

Aired: February 15, 1971

The death of a young man off the Scottish coast leads to the Doomwatch team investigating a cover up in the case of a sunken ship, and the discovery of a revolutionary life-changing science.

E10 - The Human Time Bomb

Aired: February 22, 1971

The government wants direction for the possible construction of more high-rise apartment buildings. Fay Chantry is asked to live in one and supply a report based on her experiences.

E11 - The Inquest

Aired: March 01, 1971

An inquest is held into the death of a local girl from rabies. How was she infected? A local woman thinks she knows, and she doesn't believe dogs are involved.

E12 - The Logicians

Aired: March 15, 1971

A powerful antidote formula has been stolen near a school full of gifted boys. Are they responsible, and is computer technology somehow to blame?

E13 - Public Enemy

Aired: March 22, 1971

A young boy dies while attempting to retrieve a ball from a high roof, but the cause of his death is not from falling. Doomwatch investigate.