Includes previously unreleased episode. The TARDIS lands in the lost city of Atlantis, where the crazed Professor Zaroff has convinced the Atlanteans that he can raise their city from beneath the sea. But the Doctor discovers the terrible truth behind Zaroff’s plan – he intends to destroy the entire planet. With the doomsday clock ticking, the Doctor and his companions must battle to prevent the apocalypse... Episodes 2 and 3 of this adventure feature fully restored picture and audio. The missing Episodes 1 and 4 are presented using photographic stills and a restored soundtrack.