A violent alien is sentenced in his planet to be submitted to an involution to the human form and is left on Earth. The hunters Bob Laney and his son Kip witness the fight between the two aliens and Bob shoots the alien pilot that flees in his spaceship. Kip looks for help while Bob assists the alien in human form. Out of the blue, the alien's head explodes and Bob's head is severed by the alien that uses his head. He meets the homeless Julius that helps him to find shelter and food. Meanwhile Kip is arrested and Detectives Diana Pierce and her partner Charles Krieger are assigned by Captain Scarcelli to investigate the case. They interview Kip, who tells what he has witnessed, and they believe he was high and haywire. But when Justus is murdered and Bob's head is left near his body, Diana believes something weird might be happening.—Claudio Carvalho, Rio de Janeiro, Brazil