“Horse of Destruction”, Scene 20: TARDIS Interior

On these albums

Doctor Who: The Myth MakersDonald Cotton starring William Hartnell, Maureen O’Brien & Peter Purves · 2001Soundtrack

Doctor Who: Adventures in HistoryWilliam Hartnell, Patrick Troughton with linking narration by Peter Purves & Frazer Hines · 2003Soundtrack

Doctor Who: The Lost TV Episodes - Collection OneVarious Artists · 2010

Source: MusicBrainz recording 3648f2d7-d649-4cdc-9f0a-ca7dd3cd8962 (CC0).