Roberto is a doctor in a small town near Naples. He suffers from a severe heart disease and he is heading toward an American hospital for a dangerous surgery with little or no hope of surviving. Therefore he talks to his best friend since childhood, Michele, a columnist at the local newspaper, explaining his last and long-wanted desire: having sex once with his Swedish beautiful wife, Frida.
Having just returned from a mission to Mars, Commander Ross isn't exactly himself. He's slowly becoming a terrifying alien entity with one goal -- to procreate with human women! When countless women suffer gruesome deaths after bearing half-alien offspring, scientist Laura Baker and hired assassin Press Lennox use Eve, a more tempered alien clone, to find Ross and his brood.
When guardian angel Seth -- who invisibly watches over the citizens of Los Angeles -- becomes captivated by Maggie, a strong-willed heart surgeon, he ponders trading in his pure, otherworldly existence for a mortal life with his beloved.