Moonbase 3 - Season 1 (1973)

Astronaut Harry Sanders suffers a mental breakdown while piloting a shuttle from the Moon back to Earth, causing an accident that kills him and his passenger, Moonbase 3 director Tony Ransome. Under political pressure to close the Moonbase following the deaths, the Director-General of the European space programme appoints David Caulder to take over as Director of Moonbase 3 and investigate the accident.

When two seismologists mysteriously vanish in the Mare Frigoris region, Caulder bans all travel into the area, a decision that upsets Dr Heinz Laubenthal who is conducting research in the area but won't reveal what he is working on. Some time later, Laubenthal is killed in an explosion in his laboratory. Investigations reveal that the lab walls were breached from the outside and strange tracks are found leading from the lab in the direction of the Mare Frigoris. As rumours of space monsters begin to disrupt life on the moonbases, Caulder leads a team into Mare ...

While Caulder is pressurised to deliver results from Moonbase 3's research programme under threat of budget cuts, the CORA radio astronomy project is thrown into disarray by a series of accidents. As the situation develops it becomes apparent that one of the three CORA scientists - Adam Blaney, Bill Knight and Kate Weyman - is suffering from a mental breakdown and is sabotaging the project.