Timeslip - The Day of the Clone. Complete 8 part adventure on two original ITC VHS tapes.
"Liz and Simon have escaped the destruction of Earth in the future and returned to 1970. However, Liz has now inexplicably disappeared, and Simon decides to find her; his search takes him to Traynor's newly founded Ministry, where he meets several members of staff who seem to be the originals of the clones staffing the Technocrat headquarters in 1990. Learning of a mysterious research establishment designated R1, Simon decides to investigate; sneaking inside, he soon finds Liz imprisoned in a room without windows, and manages to set her free. Together, the two children explore the complex and find it full of elderly people; however, before they can learn more, Liz and Simon are discovered by Traynor and his men, who try to capture them. With the help of an old lady named Maria, Simon and Liz manage to escape, and, after heading for the abandoned naval base where the time barrier is located, they travel back to the research institute in 1965. Here they learn that R1 was established by Morgan Devereux, and that a number of young people – including Maria - have volunteered for scientific tests. Liz and Simon realise that the volunteers they met in 1970 have all been prematurely aged by an early version of the longevity drug, and that Devereux’s death in 1969 was a result of him trying the experimental drug on himself. The children also meet a younger version of Traynor, who is attempting to learn the truth behind secret operations happening at the institute. Having uncovered explanations for The Ice Box and the Technocrat Masterplan, Simon and Liz are then captured by Devereux, and subjected to a deadly experimental sonic beam. Meanwhile, in 1970, it seems that Commander Traynor’s plans are about to come to fruition - but is he the real Traynor..?"
Classic sci-fi which is hard to come by