Episode 12, 'The Time of the Ice Box', tx. 14/12/1970

Young time-travellers Liz and Simon have been caught up in events in the so-called 'Ice Box' Antarctic scientific research station in 1990, 20 years into their own future. Liz leaves the base to find the time barrier portal back home to 1970 but on her way there Liz discovers ice cocoons in the tundra. Cracking one open she finds her own father, Frank, buried inside it. She collapses.

The base staff - Dr Bukov, Larry, and Beth (a future projection of Liz) - argue over the cause of numerous recent system malfunctions, including the death of colleague Edith Joynton through a misadministered dose of experimental longevity drug HA57. Bukov believes Director Devereaux is at fault, which Beth refuses to believe.

Liz demands to know why her father has been subjected to this suspended animation experiment. She argues with her future self, Beth, who seems to be emotionally unaffected by her complicity in her father's cryogenic experiment, scheduled to last 10 years.

A furious Devereaux blames Bukov for the recent outages - cornered, Bukov informs his 'superior' that he has been conducting reports on Devereaux all along, as part of his mission.

There is another malfunction, the base's heating systems dropping three degrees in 30 minutes. Yet again Devereaux refuses to believe this could be his fault.

Liz and Beth argue over their actions at different times in their shared lives. Simon interrupts them when he emerges from the Director's office and urges them to come and see a computer display. The images it projects confirm the 'Devereaux' who runs the base is a clone, part of the base's research mandate. The clone is also investigating the effects of the longevity drug.

Bukov plays back the computer log tapes, which confirm the Director blacked out at the vital moment that he was administering Dr Joynton's longevity drug dosage. Unable to comprehend his mistake, Devereaux's clone has some sort of breakdown. He breaks free and flees the base. Since Devereaux controls the central computer via a brain link, the heating malfunction cannot be repaired. As the temperature drops to 20 below, Simon suggests they crew take some of the 'anti-freeze' suspended animation serum to keep them alive until help arrives.

Suiting up and leaving the base to find the time barrier home, Liz and Simon discover the contorted body of the Devereaux clone out on the ice, frozen to death.