There are some inexplicable events happening on the Moon in 2049, as the Doctor, Clara, and Clara’s 15-year-old pupil Courtney, discover when they find themselves on an eventful trip there this week.

After crash-landing on the lunar surface, the three are confronted by a group of human astronauts, captained by Captain Lundvik, played by In the Club star Hermione Norris. The astronauts are armed with nuclear bombs and primed for a deadly mission – to blow up the moon!

There’s more danger too, as the group is attacked by scary spider-like creatures who scuttle around in the dark. But the Doctor quickly works out the spiders are not the cause of the Moon’s problems. Rather, they are living off something much bigger and it is still growing!

Soon a very hard decision has to be made, do they destroy the moon to ensure mankind’s survival – or do nothing and risk the Earth’s destruction? It is a terrible dilemma that causes real friction in Clara and the Doctor’s relationship.