You may wish to consult The One for other, similarly-named pages.

The One was a sentient ship in the shape of a small planetoid that was created by the people of Andromeda before they became extinct. It created and was tended by the Aala, robotic androids in the form of blond humanoids. There was a chamber near the planetoid's core where the ship could directly communicate with other people from behind a glass screen. After its creators' extinction, it believed itself to be the ruler of that galaxy. Because the Andromeda galaxy was approaching a region inimical to life, it led an armada of smaller ships to the Milky Way, where it would eliminate the species residing there in order to make room for the Andromedans.

The One was psychologically unable to cope with defiance and violence, so when the First Doctor refused to go along with its plan, it malfunctioned. (PROSE: Doctor Who and the Invasion from Space)

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