As a group of scientist and reporters watch the night skies for “flying saucer people,” several meteors come crashing to the ground. One slams into the foot of a mountain. Princess Salina Salno of the Himalayan country of Selgina is fleeing to Japan, under a threat of assassination. She is mesmerized by a bright light and hears a mysterious voice urging her to get off the plane. It explodes moments after she steps off.
A prophetess, claiming to be from Mars, appears to warn people of future trouble. She says Earth is the brink of destruction. Detective Shindou, who was assigned to protect the princess before her plane blew up, is alarmed when he notices the similarities between the Martian prophetess and Salno, and begins to guard her unofficially. Meanwhile, the assassins travel to Japan to determine whether the prophetess is the princess, and kill her if she is.
The prophetess warns visitors at a volcano that Rodan is buried beneath and they should leave immediately. They refuse to listen, and the pterodactyl-like creature breaks free. Later, she predicts that a ship about to set sail will be destroyed. She is taken off the ship by the sister of Detective Shindou, reporter Naoko Shindou. They are followed by the assassins to a hotel. Shortly afterwards, Godzilla destroys the ship.
Naoko leaves the prophetess in the room while she meets her brother in the lobby. The assassins break into the room get her to admit she is the princess. Just then, Shindou and and Naoko return. Shindou exchanges gunfire with the assassins, who escape. They take the princess to see a doctor.
Following Rodan, Godzilla walks ashore, destroying buildings as he continues his way inland. Scientists studying the meteor witness it growing and flashing from within. The rock cracks open and explodes revealing the flying three headed golden space beast, Ghidrah.
While undergoing psychological testing, the princess predicts that Ghidrah will destroy the Earth just as it did Mars thousands of years ago. Godzilla and Rodan are fighting nearby.
At a meeting with the Japanese Diet, the Fairy Twins of Infant Island suggest that Ghidrah could be defeated if Mothra, Godzilla, and Rodan joined forces. The meeting is interrupted when Ghidrah attacks. The monster spews lightning from each of his three mouths, ripping much of the city to shreds. The Twins sing out to the larval Mothra, who begins the trek to Japan.
Under hypnosis, the princess tells Shindou and the Doctor that several Martians escaped Ghidrah’s attack, and the descendents remain on Earth with only the power to foretell the future left from their advanced civilization. With the ongoing battle between Godzilla and Rodan approaching, the assassins break into the hospital. Shindou engages them in a gunfight, and they flee again. The princess and the hospital staff evacuate the building as the fight wages on.
Mothra arrives at the battlefield and debates the other two on whether they should combine forces to fight Ghidrah. The two creatures have had nothing but trouble with mankind, and refuse to help. The killers are careening down the highway to get away from Godzilla and Rodan, when they are caught in a rock slide created by Ghidrah. One assassin manages to escape the crushed vehicle, carrying a rifle.
Mothra fights Ghidrah alone, but is injured by one of the space monster’s lightning blasts. Godzilla, apparently have a change of heart, arrives and grapples with Ghidrah. He, too, is injured. Rodan flies in and taunts Ghidrah, drawing it away while Godzilla and Mothra recover.
With Rodan under assault, Godzilla and Mothra arrive to fight. The princess, who has slipped away from protection, is praying for Ghidrah to be defeated. The lone assassin finds her and shoots at her, causing her to fall onto a ledge. She regains her senses and is once more fully the princess, and no longer the prophetess. Shindou is again forced into a gunbattle with the assassin. He loses his gun, but tries to shield the princess. As the killer takes aim, Ghidrah blasts the top off the cliff, creating a rockslide that takes the assassin with the falling rocks.
Godzilla, Mothra, and Rodan triple-team Ghidrah. Mothra rides Rodan and sprays a cocooning spray on the the space monster, while Godzilla pulls its tail. Godzilla flings Ghidrah away, injuring the beast. Still covered in cocoon spray, Ghidrah gives up the fight and flies away.
Surrounded by a press gaggle, Princess Salno prepares to return home and thanks Shindou for saving her life. Godzilla and Rodan watch as Mothra swims off to return to Infant Island.
Human Cast: Yosuke Natsuki (Shindou), Yuriko Hoshi (Naoko Shindou), Hiroshi Koizumi, Takashi Shimura, Emi Ito, Yumi Ito (The Peanuts), Eiko Wakabayashi (Princess Salno)
Monster Cast: Godzilla, Mothra, Rodan, Ghidrah (King Ghidorah)
Notes: This is the English language translation released in the U.S. The original Japanese language version is titled Ghidorah: The Three Headed Monster, and was released in 1964. In the original Japanese version, the prophetess was from Venus, not Mars. There is a short scene with a reporter talking to the Chief of Police Detectives at the beginning that is deleted from the U.S. version. Other than that, there are a few scenes that have been trimmed in the U.S. version, including the final monster battle which seems slightly shorter.
LogBook entry by Robert Parson