Humanity finds a mysterious object buried beneath the lunar surface and sets off to find its origins with the help of HAL 9000, the world's most advanced super computer.
The TARDIS arrives in London in 1966 and the First Doctor and Dodo visit the Post Office Tower. There they meet Professor Brett, whose revolutionary new computer WOTAN (Will Operating Thought ANalogue) can actually think for itself and is shortly to be linked up to other major computers around the world — a project overseen by civil servant Sir Charles Summer.
