“The Bomb”, Inside the Castle, Refusis

On these albums

Doctor Who: The ArkPaul Erickson and Lesley Scott starring William Hartnell, Jackie Lane & Peter Purves · 2006Soundtrack

Doctor Who: The TV Episodes - Collection SixVarious Artists · 2013

Source: MusicBrainz recording 13942eaa-1271-4313-ab2b-8df30f9861bc (CC0).