The Troubled Spirit. Season 1, Episode 22. First broadcast Thursday 5 February 1976.

The 70s have come roaring back on Moonbase Alpha this week — with a séance, some dank hydroponic weed, and a beardo hippy and his Coral Electric Sitar. All of which inevitably summons an irrational paranormal phenomenon intent (as always) on killing everyone on the base. But not before some urgent and profound philosophical questions are raised, including Why?, What on earth is going on here? and Death, eh? What’s with that?