NASA astronauts encounter a damaged alien space craft while orbiting the moon and discover inside it a mysterious alloy shell as well as the skeletal remains of humanoid that carbon dates to 14000 years old. The shell hosts a hostile robotic species with an incredible intellect that can use pieces from whatever is lying around to create a body so it can move about After returning to earth, the robotic monster goes on a rampage, laser blasting military personnel and anyone else in its way. When it is finally subdued, the astronauts go back to the moon to see if there's any other signs of life. They find the remains of a once thriving alien civilization that has been reduced to rubble. What they don't realize is that the species which left the humanoids dead so long ago have waited for the right kind of parts needed to juice up their ship and attack Earth.
