The first manned expedition to Mars is invaded by an unknown life form, which stows away on the rescue ship.

Top Cast

Marshall ThompsonCarruthers

Shirley PattersonAnn Anderson

Kim SpaldingVan Heusen

Ann DoranMary Royce

Dabbs GreerEric Royce

Paul LangtonCalder

Robert BicePurdue

Richard BenedictBob Finelli