This is an episode that begins in a dark, dismal future type setting with an astronaut, arriving through a weird distortion in space, investigating the surroundings of a ravaged and destroyed Earth. In this hellish landscape, the astronaut encounters a lone mutated survivor, played by Martin Landau. After the astronaut disappears, the mutant takes his ship back through the tear in space to present day Earth in a desperate attempt to prevent the armageddon of the future.
A fascinating episode for anyone to watch with ideas that have appeared time and again in many science fiction tales elsewhere. Well acted and plotted...solid watching!