Major Ben McBride (Patrick Wayne) organises a mission to the Antarctic wastes to search for his friend Bowen Tyler (Doug McClure) who has been missing in the region for several years. A British naval survey ship takes them to Caprona. McBride's party: the paleontology Norfolk (Thorley Walters), gunner and mechanic Hogan (Shane Rimmer) and photographer Lady Charlotte 'Charlie' Cunningham (Sarah Douglas (actress)) fly over the mountain wall of Caprona in an amphibious aircraft, but are attacked by a pterodactyl and forced down.