Parts: 4
Writer: Brian Hayles
Airdates: 2 April 1966 - 23 April 1966
Production Code: Y

Episode Titles: The Celestial Toyroom; The Hall of Dolls; The Dancing Floor; The Final Test

Doctor: first
Companions: Steven, Dodo

Megalomaniac of the Week: Toymaker

Story: As the TARDIS makes its next landing, the Doctor turns invisible and intangible, meaning that he cannot operate the TARDIS controls to dematerialize. Realizing that he will have to confront their enemy before he can regain his form, the Doctor suggests they leave.

The TARDIS crew find themselves in the lair of the Celestial Toymaker, a being of immense power and equally immense evil whose sole amusement is in trapping space travellers and turning them into his toys. The Toymaker appears and taunts them, then spirits away the TARDIS before vanishing along with the Doctor.

Steven and Dodo are forced to play a series of innocuous-looking games in order to get the TARDIS back. If they lose a game, they also lose their free will. Meanwhile, the Doctor is put to the task of solving the Toymaker's complex Trilogic Game in exactly 1023 moves - and to up the ante, Steven and Dodo must finish their games before the Doctor finishes his...if they finish them at all. One wrong move will make them all into mindless playthings of the Toymaker...and the Toymaker's creations are cheating.