In the desert of New Mexico, a mysterious U. F. O. is detected close to Gamma Base, an army facility where a new weapon known as the Gamma Bomb is due to be tested. The inventor of the bomb is Dr. Bruce Banner, assisted by his fiance Betty Ross and the edgy Dr. Carlson, who is very eager to get a hold of Banner's Gamma formula. The U. F. O. is shot down by fighter jets, but not before an escape pod is secretly jettisoned. As the countdown to the Gamma Bomb's detonation continues, teenager Rick Jones accidentally breaks down in the test area. Banner asks Carlson to halt the countdown while he rescues the kid, but Carlson lets it continue. As Banner gets to Rick, the Gamma Bomb explodes. Banner gets Rick to safety in a ditch, but he is bombarded with the full force of the Gamma Rays. That night, in the base hospital, Banner and Rick are being held for observation, while Dr. Carlson assures his true superior inside the U. F. O. escape pod that he will be able to steal Banner's formula. As Banne