When aliens come to Earth to ask for our help, a few suspicious humans discover their horrific true intentions and prepare to resist. Aliens pretending to be friendly come to Earth and are received openly. The aliens have masqueraded themselves to look just like humans. When it is discovered that the aliens' planet is dying and that they have come to rape the Earth of its natural resources, the war for Earth begins. An important key to the humans' success is distinguishing the their own from the aliens.The main cities of Earth are surprisingly visited by fifty-one huge alien spacecrafts, and their leader introduces themselves as a friend people looking for cooperation with earthlings. Sooner, they blame the scientists of sabotage and uprising against the visitors. The journalist Mike Donovan (Marc Singer) discloses the real intentions and the reptile appearance of the aliens, while groups of people organize resistance against the invaders.