Sarah and David Kirsten are tourists from the 21st century who take a forbidden holiday in 1938 Mexico. But enforcers from the future, trying to keep the time-stream free from pollution and paradox, are on their trail. Can they evade their pursuers without betraying their origins? Written by
Did You Know?
This episode was broadcast only once and never repeated because Ray Bradbury, on whose short story it was based, requested a fee of £1000 for each repeat. The episode is now lost from the BBC's archives. Only the final credits survive and these feature in the documentary "Return of the Unknown" which is included in the BFI's 2014 DVD release of Out of the Unknown. See more