The TARDIS is in the path of molten lava and the Doctor is forced to activate the emergency unit to move it out of the time space dimension and out of reality! When the TARDIS crew land 'nowhere' they stumble into a world where fiction appears as reality and where things exist only when men believe in them. It is a world peopled by White Robots and a race of fictional characters and monsters, by Gulliver and Rapunzel, by D'Artagnan and Sir Lancelot, and worse, by the Unicorn, the Minotaur and the Medusa.
As they explore the forest of words and the maze in this Land of Fiction new horrors await the Doctor and his companions round each corner... will Zoe and Jamie be turned into fictional characters? Is the Doctor at the mercy of a higher intelligence or force outside time and space as he knows it? Can he outwit the brain that is the source of this terrifying creative power?
Episodes originally transmitted on BBC1 14/09/68 - 12/10/68.