The Doctor and Clara take the Wards to the World of Wonder, a theme park on a different planet in the future. However, it seems largely abandoned, and for good reason-it’s occupied by the military. There also happens to be a deactivated Cybermen that can play chess, but it’s actually manipulated by another person-the small man Porridge.
However, the Cybermen aren’t entirely dormant-in fact, the World of Wonders sits atop a Cybermen tomb, and cybermites-small versions of the Cybermat-are loose.
The Doctor is even partially converted, and begins a mental battle with another persona-the Cyberplanner (or “Mr. Clever”) while Clara and the military group find themselves under siege from the Cybermen army.
The Cybermen have also upgraded once again, with a new design allowing them to fly, remove key body parts to use as weapons, and super-speed. They also appear far more sleeker than their predecessors.
The Doctor tries to confound the Cyberplanner with a game of chess, hoping to outsmart his ‘other half’. He manages to do so, and this causes a strain on the Cybermen’s hive-mind, halting them. However, the military attempts to destroy the planet with a device, but Porridge-in fact, a galactic Emperor-is able to transport the survivors to safety while the Cybermen and the planet are destroyed. The Doctor also manages to reset the partial conversion of the survivors as well.
But even though he’s once again defeated one of his oldest, greatest enemies once again, one of the Doctor’s greatest struggles is about to begin.