Intro: Take one robot, render it impregnable, and add one batch of unscrupulous scientists, and a large plot to blackmail the world. Season with a Time Lord and his loyal assistant. Add a bit of brigadier and a pinch of naval doctor. Stir well for two hours. The result: who knows, or I should say, Who knows?

Outro: When, centuries hence, the Earth's destruction is assured by solar flares, a cross-section of the population will be chosen to be deep frozen and sent into space. At the predetermined time they will be reawakened if nothing untoward obtains. Rest assured, something will, which is why, one week from tonight, The Doctor and Sarah will journey to "The Ark in Space." [source: ChicagoEpguides]