Lethe (The Parliament of Rats)

Lethe was an ocean planet. It was the site of the Lethean Campaign during the War in Heaven. (PROSE: The Book of the War) The Time Lords left the planet ravaged by time fractures which eventually pulled in the Doctor's TARDIS. Lethe's human population was island-based; after their crash, the Fifth Doctor and Nyssa were rescued by the crew of the Lung of Heaven. (PROSE: The Parliament of Rats)

Lethe (The Parliament of Rats)