Niash

Niash (PROSE: The Ark) was a Guardian aboard the Ark during the 57th Segment of Time.

Biography
Niash put the whole of the Ark's civilisation aboard the Ark in danger when he inadvertently failed to check the sealing valves aboard the giant spacecraft properly.

He was put on trial by the Commander and the Monoids; and, despite the pleas of the Commander's daughter Mellium, was sentenced to 700 years of miniaturisation, the lightest sentence the Commander could impose, to be returned to normal only when he would no longer be a danger to anyone. (TV: The Ark)

700 years later, Niash was restored from miniaturisation, along with the other humans, Monoids etc., via Re-enhancing Incubators on Refusis II, where he met the First Doctor, Steven Taylor and Dodo Chaplet. Niash was relieved everyone had made it, despite his mistake, which he confessed to the Doctor and was reassured that it didn't seem to have made any difference. Having learned Niash had travelled in the time of the First Commander and Mellium, the Doctor told Niash to go and live his life to the full, as he was intended to. (PROSE: The Ark)

Behind the scenes

 * The miniaturised Guardian is never named as Niash on-screen; his name is given only in Paul Erickson's novelisation.
 * There is no scene in the televised version of the fourth episode, "The Bomb", where the Guardian is restored to his full size; this was added by Erickson for the novelisation.