简介：　　When the Viking space capsule suddenly returns to Earth from its long ago trip to Mars, it brings with it an intelligent visitor that is part &quotAlien&quot and part &quotET&quot. Encased in armor, it extends a humanlike form from its shell to examine its surroundings and shows an interest in humans including a soft caress of a female scientist prior to the Army killing it. This only enrages its sibling.