Moon Zero Two was Hammer Film’s attempt and joining in on the sci-fi market. The year is 2021, and the moon is in the process of being colonised with a number of different settlements including Moon City and Farside 5.
Two such denizens of this rough and tumble lunar society are the notorious millionaire J. J. Hubbard (Warren Mitchell )and former-astronaut-turned-satellite-salvager Bill Kemp (James Olson).
Kemp was the first man to set foot on Mars, but has since left the Space Corporation because he wants to do space exploration whereas his former employer only wants to do commercial passenger flights to Mars and Venus.
When Hubbard hears of a small 6000-tonne asteroid made of pure “ceramic” sapphire that is orbiting close to the moon, he hires Kemp to capture it using Kemp’s old “Moon 02” space ferry and bring it down to the lunar farside although it would be against the law.
However, Kemp has little choice since he has learned that his flight license soon will be revoked due to protests from the Corporation. Hubbard also reveals that he plans to use the sapphire as a rocket engine thermal insulator; he would build more powerful rockets capable of finally colonizing Mercury and the moons of Jupiter—for profit.
Meanwhile, a young woman named Clementine Taplin (Catherine Schell) arrives looking for her brother, a miner working a distant patch of moonscape at Spectacle Crater on the lunar farside. Unfortunately, the trip from Moon City on the nearside would take six days by lunar buggy. Since Kemp could go there more quickly using Moon 02, she convinces him to try to learn whether her brother is still alive. As the terrain is not entirely suitable for landing Moon 02, Kemp and Clementine travel the remaining distance by vehicle.
The two discover that Clementine’s brother is dead and soon find out that it was murder, especially as he had found a vein of nickel that would have made him a rich man. They do not have long to dwell on these revelations, as they are shot at by some of Hubbard’s men, as the millionaire was unhappy to discover that Kemp was leaving to assist Clementine.
It is eventually revealed that Hubbard is responsible for the brother’s death. He needed the claim to be abandoned in order for him to take control of the land as it was the projected landing site for the asteroid and Clementine’s brother would never have left the land after discovering the nickel vein. Hubbard blackmails Kemp into completing the job by threatening the lives of Kemp and Clementine, but in the process Kemp overcomes the millionaire. The film ends with Kemp telling Clementine that as her brother’s next of kin she now has ownership of the nickel vein and all of the sapphire, making her a wealthy woman.