On 24 May 2025, Belinda Chandra (Varada Sethu) is captured on a spaceship by robots and becomes the queen of Planet Missbelindachandra One. It seems her ex-boyfriend Alan Budd had named the star and planet for her, and she blames him for everything gone wrong since.
The Missbelindachandra One planet had been kept peaceful by both humanoids and A.I. until the robots took over and the people rebelled. The robots are controlled by the Great AI Generator, who intends to merge with Belinda. The Doctor (Ncuti Gatwa) who had been chasing Belinda, arrived six months before her and is now the planet’s historian. He has discovered that the robots cannot hear the ninth word in every speech, and using this quirk, the Doctor and the Rebels rescue Belinda despite several Rebels being killed.
The Doctor knows that the robots had the same version of the star-naming certificate that Belinda has, but it is 5000 years older. Belinda allows herself to be captured to save the Rebels. She and the Doctor are taken to the Great AI Generator, who is not actually an artificial intelligence but Alan himself (Johnny Green). He had been captured when he thought life on the planet was only a game and he started the war because Belinda had broken up with him.
Using every ninth word, Alan communicates that he is in pain. He and Belinda touch certificates, which causes them to experience all of time simultaneously. Alan is reduced to a sperm and an egg, but the Doctor rescues Belinda.
The humanoids and the robots are now free and they rebuild their society. The Doctor takes Belinda in the TARDIS. He mentions having met her distant descendant Mundy Flynn. Belinda wants to be taken home, but the TARDIS is unable to return to 24 May 2025, so she travels with the Doctor. As the TARDIS dematerializes, Terran landmarks and a torn calendar reading 24 May 2025 drift in space behind it.
The episode was written by Russell T. Davies, originally as a one-off, but then it became a series premier introducing a new companion. Belinda refers to the “planet of the incels”. Because Sethu had played a character named Mundy Flynn in the 14th episode, the latter character is mentioned as a distant descendant of Belinda. Two of the robots were puppets manipulated by the wonderfully named Stephen Love and Robert Strange, who had done puppetry in previous episodes.
The design of the planet was inspired by Forbidden Planet and This Island Earth, and it has a definite 50’s vibe. One of the cleaner robots was designed to resemble the 1954 Chevy Bel Air and the 1972 Fiat 500—with touches of Wall-E, Johnny 5, R2-D2, and others. Nicholas Briggs, whom we remember from the voices of the Daleks, did the robot voices in this episode. The rebel base has X-ray blankets that reveal a person’s identity—except the Doctor.