"The Battle of Ranskoor Av Kolos" is the tenth and final episode of the eleventh series of the British science fiction television programme Doctor Who.
Set on the planet Ranskoor Av Kolos, the episode involves the alien time traveller the Thirteenth Doctor (Jodie Whittaker) and her companions Graham O'Brien (Bradley Walsh), Ryan Sinclair (Tosin Cole), and Yasmin Khan (Mandip Gill) working to stop the alien Stenza Tzim-Sha (Samuel Oatley) from using the powers of the psychic race the Ux to shrink the Earth in revenge for his previous defeat and exile thousands of years earlier.
The Doctor and her companions find a large number of wrecked spaceships scattered on the planet's surface, as well as a psychic field that alters one's perception of reality.
Once the group enters Tzim-Sha's ship, Graham and Ryan search for the kidnapped crew whilst Yasmin helps Paltraki remember his mission.
Tzim-Sha spent the next three millennia combining the Uxs' powers with Stenza technology to create a life support system and a weapon that shrinks planets like the one from Paltraki's ship.
[11] The episode received an official total of 6.65 million viewers across all UK channels, making it the 18th most watched programme of the week, and it had an Audience Appreciation Index score of 79.