The Doctor (Peter Capaldi) takes Clara (Jenna Coleman) and her student Courtney Woods (Ellis George) on a trip to the moon in 2049. They arrive aboard a space shuttle filled with nuclear bombs coming in for a crash. Captain Lundvik (Hermione Norris) explains that the whole crew is on a suicide mission to destroy the moon. As the Doctor can tell, the moon’s mass has increased greatly, which would cause huge tides everywhere on Earth.

They check out a nearby survey base, where the miners are all dead, entombed in webbing. The moon is starting to break up. Lundvik’s crew is killed by a spider-like creature, but Clara has a disinfectant spray which kills it. The Doctor finds that the moon has always contained the egg of a giant creature inside, which is now ready to hatch. Lundvik is even more determined to blow up the moon.

As humans, Clara, Courtney, and Lundvik get to decide. Lundvik prepares a remote trigger for the bombs. They think they should let Earth’s population make the final decision. On broadcast channels, Clara asks the world to leave their lights on if they want to let the creature live and turn them off if it should be destroyed. One by one, the lights go out. But at the last second, Clara stops the countdown. The Doctor picks them up and takes them to Earth as the moon begins to crumble.

The winged creature inside hatches from its shell and flies off. It lays another egg that becomes a new moon. The Doctor thinks the sudden interest in the moon will revive interest in outer space. Clara berates the Doctor for forcing her to make the decision on the fate of humanity, while the Doctor maintains he must not make such decisions himself. Clara does not want to see him again and returns to Danny.

The story was originally written for Matt Smith. Reviews were extremely polarized. Jenna Coleman’s performance was praised, particularly her last dust-up with the Doctor, but pretty much everything else was a source of disagreement. The science was criticized, of course. My first thought was that blowing up the moon would cause more damage on Earth than abnormally high tides. A creature inside the moon is more primitive mythology than science, like Earth resting on the back of a turtle supported by elephants. But Doctor Who has often slipped into myth and legend. Perhaps the story should have been portrayed with black cut-outs in front of a lantern. Then again, Hot House, or the Long Afternoon of Earth, a highly respected novel by Brian Aldiss, featured a great spiderweb from the Earth to the Moon.

The sets were criticized as dull and gray, but it’s the moon. Some people decided the whole thing was about abortion and argued appropriately. The orange spacesuit should be familiar to Doctor Who fans by now, as it has been worn by David Tennant and Matt Smith often enough. The Doctor offers Courtney the chance to be the first woman on the moon, but the first woman on the moon was Martha Jones, with her entire hospital, in Smith and Jones. At least, the early scenes were appropriately creepy and weird.