The Ark is the sixth serial of the third season of the British science fiction television series Doctor Who, which was first broadcast in four weekly parts from 5 to 26 March 1966. The serial is set at least ten million years in the far distant future. In the first two episodes the time traveller the First Doctor (William Hartnell) and his travelling companions Steven Taylor (Peter Purves) and Dodo Chaplet (Jackie Lane) arrive on a generation ship that Dodo names "the Ark". The Doctor searches for a cure for a fever that has spread across the human and Monoid races on board the ship, who have no immunity to it. The last two episodes are set 700 years later, and involve the Doctor, Steven and Dodo working with the Refusian race to stop the Monoids from wiping out the last of humanity with a bomb. The story constitutes Dodo's first journey as a companion to the Doctor. It is also the earliest serial of the third season to exist in its entirety. Plot At least ten million years in the future the TARDIS materialises on a vast spacecraft with its own miniature zoo and arboretum. The First Doctor and Steven are explaining the basics of their time travel ability to their new companion Dodo Chaplet when she starts to show signs of a cold. The three are taken to the control chamber of the vessel by the mute single-eyed Monoids. The Monoids live in peace alongside the humans who command the spaceship, their own planet having been destroyed, but they often do much of the menial work. The humans explain that the Earth is about to be destroyed because of the expansion of the Sun, and that the ship is an "Ark" sent into space with the last remnants of humanity, civilisation, and various flora and fauna. The human Guardians in charge of the craft run a tight ship: failure to conform to their rules means either death or miniaturisation until they reach their destination, an Earth-like planet called Refusis II, which takes nearly 700 years to get to. As an amusement during the journey a vast statue is being carved by hand, depicting a human being. Dodo's cold spreads among the Monoid and human populations, who have little natural immunity. When the Commander of the Ark collapses with the malady Zentos, the Deputy Commander, assumes that the travellers