Finding cave refuge, the crew notice in the distance the primitive human descendants of that civilization emerging from behind boulders and creeping toward them. Amazed, Dr. Eckstrom comments "From Atomic Age to Stone Age". Soon after leaving, two of the explorers encounter a dark-haired woman who has lost her footing and rolled down a hill toward them; she is blind, with thick, milky cataracts on both eyes. She screams upon hearing their oxygen mask-distorted voices. The radiation burned tribesmen attack, throwing large rocks and stone axes. Armed with only a revolver and a bolt-action rifle, the explorers defend themselves, purposely missing the primitives. Dr. Eckstrom is killed by a stone axe; navigator Chamberlain (Hugh O'Brian) is badly injured by a large thrown rock. The survivors finally make their way back to the ship.