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

Marshall Thompson
as Carruthers

Shirley Patterson
as Ann Anderson

Kim Spalding
as Van Heusen

Ann Doran
as Mary Royce

Dabbs Greer
as Eric Royce

Paul Langton
as Calder

Robert Bice
as Purdue

Richard Benedict
as Bob Finelli

Richard Hervey
as Gino

Thom Carney
as Kienholz
John Chard
It has to kill us or starve and we've got to kill it or die. It's the future, 1973, and the first manned expedition to Mars is marooned. When a rescue team finally reach the stricken ship they find only one survivor - the leader, Col. Edward Carruthers. He claims that an alien life form killed h...