Trying to escape from a volcanic eruption, the Doctor activates the TARDIS' emergency circuits, taking his ship out of real time and space altogether. However, the void is inhabited by a hypnotic force which lures Jamie and Zoe outside, keeping the Doctor distracted until the strain on the TARDIS becomes too great and the ship explodes. The Doctor and his companions find themselves in a Land of Fiction, where wordplay can be deadly and fictional characters come to life. The travellers must make their way to the castle at the centre of the Land, while the Master of the Land of Fiction waits for them to make the wrong move and transform themselves into fictional characters and thus pawns under his control.