To escape from the lava flow at the end of The Dominators, the Doctor hits the emergency switch, zapping the TARDIS out of space-time and into a featureless white void, where they are attacked by white robots (some "void"). And then things get weird. They flee back to the TARDIS which promptly explodes, leaving Jamie and Zoe clinging to the control console in space, while the Doctor appears to be dead. Suddenly, they find themselves in what appears to be a fictional landscape, menaced by lifesize clockworks soldiers and meeting characters like Gulliver and Rapunzel.