The TARDIS lands in a space museum on Earth in the late 21st century, where the Second Doctor, Jamie and Zoe learn that contact has been lost between Earth and the Moon. In this era, instant travel — T-Mat — has revolutionised the Earth. Its people have lost interest in space travel. The Doctor and his companions travel to the Moon in an old-style rocket and reach the Moonbase, control centre for T-Mat, only to find a squad of Ice Warriors have commandeered the base and plan to use the T-Mat network to their advantage.
La TARDIS llega a Londres en 1966 y el Primer Doctor y Dodo visitan la Torre de Correos. Allí conocen al profesor Brett, cuya nueva y revolucionaria computadora VOFA (Voluntad de Operación de Funcionamiento Análogo) puede pensar por sí misma y pronto se conectará a otras computadoras importantes en todo el mundo, un proyecto supervisado por el funcionario Sir Charles Summer.
