2x21 - The Lost World

During a powerful thunderstorm on the plateau, all five of our heroes experience dreams and visions of their ""lost"" colleague, Summerlee, who had disappeared into a raging waterfall and presumed dead. Malone sets off after this ghost, and Challenger Marguerite and Roxton follow Ned. The three are ambushed by cannibals who fancy Marguerite's arm for an aperitif. Roxton and Challenger break free and save her, and then the three resume their hunt for Malone, only to be trapped by a hungry T-Rex. Ned meanwhile, has fallen and knocked himself out. He regains consciousness, concussed and thirsty, and follows Summerlee's ghost along a dry riverbed. He stumbles and twists his ankle, but still hobbles on. Summerlee appears to be leading him to the now dry waterfall where he was last seen.