“The Traitors”, Scenes 3-5: Mavic Chen's SPAR & Airlock

On these albums

Doctor Who: The Daleks’ Master PlanTerry Nation & Dennis Spooner starring William Hartnell, Peter Purves & Adrienne Hill · 2001Soundtrack

Doctor Who: The Lost TV Episodes - Collection TwoVarious Artists · 2011

Source: MusicBrainz recording 713c2b3b-aae9-4b56-ab3e-0f7675f39ec7 (CC0).