World Without End (1956)
After a pioneering mission to Mars, four astronauts encounter a time warp that propels them to a ravaged Earth in the 26th century. Initially oblivious to their surroundings, they discover a breathable atmosphere and begin to explore the chaotic landscape. They stumble upon a starkly divided world: deformed mutants struggle for survival on the surface, resembling primitive tribes, while the unblemished inhabitants thrive underground. However, this hidden society faces extinction due to a dire shortage of water, air, and sunlight, prompting the astronauts to confront the dire consequences of humanity's past choices.
