"Kill the Moon" is the seventh episode of the eighth series of the British science fiction television programme Doctor Who, written by Peter Harness and directed by Paul Wilmshurst. The episode stars Peter Capaldi and Jenna Coleman, with Hermione Norris guest starring. The episode is particularly notable for receiving wildly polarizing reviews from television critics. Whilst some critics acclaimed the episode and labelled it the best of the season, others criticised its scientific inaccuracy and thematic content.

After the events of "The Caretaker", Clara Oswald warns the Doctor that her student, Courtney Woods, is still interested in his TARDIS and is trying to clean up the mess inside it she made previously. As they enter the TARDIS, the Doctor stops Courtney from cleaning and offers to take her and Clara on a trip in the time machine.

They arrive in 2049 aboard a space shuttle filled with nuclear devices on a crash course for Earth's moon. They survive and meet the shuttle's crew, led by Captain Lundvik. Lundvik explains they are on a suicide mission to destroy the moon; some years past, the moon's gravitation influence suddenly changed, causing massive high tides on Earth wiping out much of humanity, and destabilising the orbit of many of mankind's artificial satellites. Lundvik, who had wanted to become one of Earth's space-faring astronauts, offered to go on this mission to save humanity. Privately, Clara asks the Doctor about this point in time, knowing the moon exists in Earth's future, but the Doctor himself is not clear, as this is a point of time in flux.

They travel to a nearby Mexican lunar colony, finding it covered in cobwebs and the colonists dead, entombed in similar webbing. The Doctor confirms the colony's readings that the moon has gained over one billion tons of additional mass. They are attacked by a spider-like creature that kills Lundvik's crew, but the disinfecting spray Courtney brought kills the creature; the Doctor compares it to germs, and wants to study it further. After seeing Courtney safe to the TARDIS, they investigate a crevasse where thousands of the spider-like creature wait, and the presence of amniotic fluid nearby. The Doctor surprises Clara and Lundvik by diving into the crevasse, promising to meet them later.

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