Considered to be one of the most ambitious films made by the Spence Brothers, this stone-age alien extravaganza has everything a true sci-fi fan needs in spades. The mission is simple: aliens must capture and record living specimens from earth. However a violent earthquake forces the ship to take off whilst a giant robot, used to collect specimens, is swallowed up in the eruption. During quarry excavations in the present day the robot is re-animated, and the mission is still on.