Titan III
Titan III, or Titan 3, was a barren and desolate planet, though the Sixth Doctor also called it an asteroid on one occasion. According to one account, it might have been the most remote planet in the Mutter's Spiral, so far below the plane of the ecliptic that no one ever came closer than a hundred thousand light-years. (PROSE: The Quantum Archangel) According to another account, it was in Maston Viva in Baxus Major. (PROSE: The Twin Dilemma)
It was the location of a safehouse used by Azmael after abducting Romulus and Remus Sylvest in 2310. In his pursuit of the twins, Hugo Lang was shot down over the planet and crashed there. He was rescued by the Sixth Doctor, who had come to Titan III to become a hermit and atone for almost killing Peri Brown shortly after his regeneration. The Doctor and Peri were captured by Azmael and imprisoned, but unknown to him, Noma had set the base to self-destruct. However, the Doctor and his friends escaped and pursued Azmael to Jaconda. (TV: The Twin Dilemma)
The presence of Titan Melancholia on the planet meant that visitors became depressed. (PROSE: The Twin Dilemma)