Space:1999 The Full Circle

*Space: 1999* episode "The Full Circle," the crew of Moonbase Alpha encounters a mysterious mist that transports them back in time to a prehistoric world. They find themselves transformed into primitive, cave-dwelling versions of themselves, losing their advanced knowledge and technology. Commander Koenig and Dr. Russell must find a way to reverse the transformation and return to their own time. The episode explores themes of evolution, the nature of humanity, and the struggle to retain one's identity in the face of regression.