Gamera the Flying Turtle falls under the spell of evil aliens, but two children free him and he returns to fight the aliens' monster, Viras.
A group of aliens from another planet head for Earth with the intentions of conquering it. Their first ship is destroyed in transit by the giant flying turtle Gamera. A second ship makes it to Earth and captures two Boy Scouts and holds them captive so that Gamera will not attack them. The aliens then implant a remote control device into the monster's neck and use the great turtle to attack Tokyo.
