18:15Doctor Who (1963–1996)Season 15The Invisible Enemy: Part 3BBC One Duration: 25 minutes Audio described Signed Sat 15th Oct 1977, 18:15 on BBC One North WestAvailable for yearsWatch nowThe Doctor and Leela have been cloned and miniaturised and injected into the Doctor's body. There they must fight the virus on a microscopic level before time runs out.GenresDramaSciFi & FantasyBrandDoctor Who (1963–1996)SeriesDoctor Who (1963–1996): Season 15 Source: BBC Online