Alpha Child. Season 1, Episode 7. First broadcast Thursday 16 October 1975.

An eerie green glow is making for Alpha, bringing with it the most terrible consequences, as the first baby born on the base undergoes two periods of ultra-rapid growth, becoming in mere seconds a terrifying English moppet and shortly after that Julian Glover in a skimpy miniskirt. Is this the next stage in human evolution, or merely an invasion by an alien who wants to give his mother a nice makeover and a good rogering before (inevitably) killing everyone on the base?

Voyager’s Return. Season 1, Episode 6. First broadcast Thursday 9 October 1975.

This month, John and Victor decide that the pursuit of a shoebox full of polaroids is a good reason to risk the crew’s lives — entrusting their safety to this week’s guest star, a Nazi rocket scientist or something with a secret past that inevitably involved killing a whole bunch of people in an easily foreseeable accident. However, things hot up with the arrival of three steatopygous spaceships captained by a heavily-made up alien with no facial expression, who is understandably resolved to kill everyone on the base and all the loved ones they left behind them.

Death’s Other Dominion. Season 1, Episode 5. First broadcast Thursday 2 October 1975.

This month, we’re faced with an alarming metaphysical choice: eternal life among a bunch of absurdly hot models in Hugh Hefner’s second least favourite Swiss chalet, or a normal lifespan cleaning up the corridors of Moonbase Alpha after its latest nuclear catastrophe. Victor, Helena, Bob and Alan all want to make the obviously correct (if basic) choice, but their fun is inevitably spoiled by miserable old John Koenig and the second law of thermodynamics.

War Games. Season 1, Episode 4. First broadcast Thursday 25 September 1975.

This month’s ethereal immortal beings in a surreal Pinewood studio are Isla Blair and Anthony Valentine, who are (reasonably enough) so keen to avoid meeting the crew of Moonbase Alpha that they decide to just kill everyone on the base instead. Or do they?

Collision Course. Season 1, Episode 3. First broadcast Thursday 18 September 1975.

Moonbase Alpha is on a collision course this week, ineluctably destined to crash into a giant pustulent planet. Or is it? Commander Koenig — overcome by the charms of Queen Margaret Leighton — doesn’t think so, and so he turns up to Main Mission in his pyjamas like a Moonie and threatens to gun down anyone who attempts to prevent the collision, including, upsettingly, our own Barbara. But — inevitably — it all turns out for the best, and we end our second episode in a row staring out the window contemplating the metaphysical metamorphosis we have wrought.

Force of Life. Season 1, Episode 2. First broadcast Thursday 11 September 1975.

An eerie blue glow invades Alpha and takes control of a young Ian McShane, who suddenly becomes prone to bouts of German Expressionism and freezing attractive young people from the 1970s. A star is born this week, in Force of Life.

Breakaway. Season 1, Episode 1. First broadcast Thursday 4 September 1975.

September 13th, 1999. A nuclear waste dump on the moon is destroyed in an explosion so violent and so catastrophic that it creates a major science fiction show on ITV and the commentary podcast which tells its story. But before that, we witness some harrowing deaths, some attractive moustaches, and the quivering emotional restraint of Dr Helena Russell, from which this podcast gets its name.