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 "Alien" and part "ET". 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爱情不是寻找共同点，而是学会尊重彼此的不同。