When the Viking space capsule suddenly returns to Earth from its long ago trip to Mars, it brings with i刮伦小说500目录t 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.