During a mission to Mars, astronaut Patrick Ross is infected with alien DNA. Back on Earth he starts to transform into a terrifying alien entity with a one track mind - to mate with human women and colonise the world with his half-alien offspring.
Scientist Laura Baker and ex-military assassin Press Lennox race against time to stop Patrick. They use Eve, the beautiful half-alien clone, to lure Patrick, but Eve's instinct to mate is too strong and she escapes to procreate with Patrick to create an alien race that spells doom for mankind.
