The Testament of Arkadia. Season 1, Episode 23. First broadcast Thursday 12 February 1976.

Stranded in a cold and purposeless corner of an indifferent universe, adjacent to the end of everything, the crew of Moonbase Alpha make a discovery which changes the meaning not just of their journey but of their very existence, and which drives this week’s Large Hot Italian Guest Star and his posh new girlfriend to make an irrevocable decision.