Test space rockets exploding at liftoff and increased reporting of UFO sightings culminate in a direct attempt by alien survivors of a dead, extra-galactic civilization to invade Earth from impervious flying saucers, using ray-weapons of mass destruction.
Hugh Marlowe
Dr. Russell A. Marvin
Joan Taylor
Carol Marvin
Donald Curtis
Maj. Huglin
Morris Ankrum
Brig. Gen. John Hanley
Thomas Browne Henry
Vice Adm. Enright
Grandon Rhodes
Gen. Edmunds
John Zaremba
Prof. Kanter
Paul Frees
Alien (voice)
