Godzilla, king of the monsters, returns to threaten Tokyo once again. When a UFO is sighted over Tokyo, it transpires that it is a time travelling device with a desperate warning from the 23rd century. In the future there is no Japan - Godzilla has destroyed it in one final rampage. He must be stopped, and there is only one course of action - someone must travel back in time to stop him. However, on their return they find that there is a new threat - King Ghidorah.