[s2e8] The Impossible Planet -

This episode marks the first appearance of the Ood, who would go on to become one of the most iconic and complex recurring alien races in the series.

The episode is widely praised for its shift into genuine horror, featuring claustrophobic corridors and the unsettling "red-eye" possession of the Ood. [S2E8] The Impossible Planet

The Doctor and Rose land on Sanctuary Base 6, a human research station situated on , a planet inexplicably orbiting a black hole without being pulled in. This episode marks the first appearance of the

The story concludes in the follow-up episode, "". a human research station situated on