A military scientist (Lee Van Cleef) detects a signal from Venus that turns out to be an alien being that can communicate with him. He helps it come to earth where it aims to take over the world. It stops all the power in a town and takes over the minds and bodies of some of the people, but his friend (Peter Graves) resists the take over at great personal loss.
WHilst the plot and the monster leave something to be desired, overall Roger Corman produced an effective piece of cold war sci-fi. This was remade as
Zontar The Thing Fom Venus.