Ghidorah, the Three Headed Monster (1964)

During an unseasonably warm winter night, reporter Naoko Shindo observes members of a UFO club searching the sky for flying saucers. When the club fails to spot any UFOs, the head member laments that the aliens won't reveal themselves because they brought a non-believer into their midst. Naoko incredulously asks if they actually believe aliens exist, to which the head of the club replies that there are many strange phenomena occurring across the globe, such as the incredibly warm temperatures in the winter months. Naoko asks if he thinks the world will explode, but he replies he simply feels something terrible will happen soon. Just then, a huge meteor shower falls over Japan, with one particularly large meteor crashing into the Kurobe valley. Meanwhile, Naoko's brother, Detective Shindo, is given an assignment by his chief of police. Shindo is assigned to act as the bodyguard for Princess Maas Doulina Salno, ruler of the small Himalayan kingdom of Selgina, who will be visiting Japan to escape political opposition in her home country. While Princess Salno's plane is flying over Japan, she suddenly becomes possessed by a mysterious voice, who orders her to jump out of the plane immediately just before it is blown up by a bomb.

Professor Murai and his team arrive near Kurobe Dam and are assigned to study the meteor that crashed in the Kurobe valley. As they approach, they find that their compasses are all malfunctioning. Once they reach the meteor, they discover that it is emitting a powerful magnetic force. They immediately begin studying the strange meteor, which they discover is slowly growing in size. Elsewhere in Japan, a mysterious woman appears and begins offering ominous predictions for the future. Naoko is sent to cover the prophetess, and attempts to gain an interview with her. When Naoko asks the prophetess where she is from, she claims to hail from Venus, and warns that terrible disasters will begin to befall the planet, starting at Mount Aso. When Shindo sees a picture of the prophetess, he notices she bears a strong resemblance to the Princess, and asks the chief to allow him to pursue the case. Meanwhile, the head of the political opposition in Selgina learns that a woman strongly resembling the Princess has been seen in Japan. He orders the assassin Malmess, who had previously assassinated Princess Salno's father, to travel to Japan and finish the job, or be killed himself.

While searching for leads on the prophetess, Shindo encounters his sister, who is also looking for the prophetess to continue her story. The two of them go to a bar to meet with Murai, with whom Naoko is working on a story about the meteor in Kurobe. While they are at the bar, they see a news report on the television showing the prophetess speaking at Mt. Aso. She warns the surrounding crowds that volcanic gases accumulated inside the mountain will resurrect Rodan, but her warnings are laughed off by the crowd. However, true to her warnings, Rodan emerges from the crater and takes flight. As Rodan resumes his reign of terror across Japan, the Venusian reappears at a port, warning that the cruise ship preparing to leave there must not sail. The captain stubbornly refuses to heed her warnings, but the Shobijin, who are passengers on the ship, are intrigued by her prediction. Naoko arrives at the scene and convinces the prophetess to come with her to a hotel so she can do a story on her. Malmess and his men follow them to the hotel, and enter the room when Naoko leaves. Malmess tries to find out for certain that the woman is the Princess, and holds a knife to her throat to threaten her. Meanwhile, Shindo arrives at the hotel to try and secure the prophetess, believing her to be the Princess. When he enters the room, the Shobijin kill the lights and warn that killers are in the room. Shindo opens fire and chases the assassins off, and once the lights are turned back on he finds the prophetess meditating in a corner. Naoko asks why the Shobijin are here, and they reply that they are heeding the prophetess' warning.

True to the prophetess' prediction, the cruise ship is destroyed when Godzilla rises from the ocean and obliterates it with his atomic breath. Godzilla comes ashore in Yokohama and his attention is caught by Rodan flying overhead. Godzilla follows Rodan to the Mount Fuji area, where they begin a fierce battle. Shindo brings the prophetess to the laboratory of Dr. Tsukamoto, who attempts to diagnose whatever mental illness is affecting her. All of the doctor's attempts to get the truth out of the prophetess fail, and she still claims to be a Venusian. She claims that thousands of years ago, Venus was home to a great civilization far more advanced than Earth's. However, an evil space monster called King Ghidorah arrived on the planet and completely annihilated its civilization in a single day. The few Venusians that survived the attack fled to Earth, where they were assimilated into the planet's civilization and gradually lost their identity. She goes on to claim that she is one of the last descendants of the Venusian refugees, and retains her ancestors' power of prophecy. She warns that King Ghidorah has already arrived on Earth, and will do the same to it what he did to Venus thousands of years before.

In Kurobe, Murai and his men notice that the meteor's magnetism has seemingly stopped, and they have not noticed any more strange phenomena recently. Suddenly, the meteor begins emitting strong magnetism once again, and they resume their intense study of it. While they are sleeping one night, the meteor splits open and begins spewing sparks. Murai holds up a Geiger counter, which registers a strong radioactive reading. Soon, a pillar of flames blasts from the meteor into the sky, where it materializes into King Ghidorah, a three-headed golden dragon. King Ghidorah flies over Japan, blasting apart its cities with his gravity beams. With King Ghidorah, Godzilla, and Rodan terrorizing Japan, the government convenes an emergency meeting at the National Diet Building. Murai, Naoko and the Shobijin attend the meeting, and propose a desperate plan to get Mothra to battle King Ghidorah, like she did against Godzilla previously. The Shobijin warn that Mothra is still a larva, and cannot hope to stand against King Ghidorah on her own. But, they propose that if Mothra were to join forces with Godzilla and Rodan, the three of them could overcome the space monster. As King Ghidorah flies over Tokyo, the Cabinet begs the Shobijin to call Mothra. The Shobijin oblige, and Mothra sets off from Infant Island.

Back in Tsukamoto's laboratory, the doctor prepares to administer electroshock therapy to the prophetess and hopefully clear her mind. Shindo sets the voltage to the required level, after which Malmess sneaks in and sets the voltage to a lethal level, letting Tsukamoto kill the princess for them. Just before the lethal shock can be administered, Rodan drops Godzilla onto a power pylon, knocking out all power in the area. As Malmess and his men breach the laboratory and try to shoot the princess, Naoko and Murai arrive to tell Shindo about their plan. Shindo engages in a brief shootout with Malmess and his men before they flee, then gets into a car with Tsukamoto, the prophetess, Murai, Naoko and the Shobijin. Once they reach a traffic jam, they exit the car and climb to a hill to witness Mothra attempt to convince Godzilla and Rodan to help her. As Godzilla and Rodan throw rocks back and forth at each other, Mothra arrives at Mt. Fuji and restrains them with silk. Godzilla and Rodan reluctantly stop their fight and listen to Mothra. The Shobijin translate the monsters' conversation, which begins with Mothra asking Godzilla and Rodan to help her fight King Ghidorah. They both refuse, saying they have no reason to help humanity, as humans have always attacked them. Mothra insists that the Earth belongs to all beings, not just humans or monsters, but Godzilla and Rodan each stubbornly refuse, each demanding the other apologize. With her pleas falling on deaf ears, Mothra gives up and attempts to battle King Ghidorah by herself. King Ghidorah lands near Mt. Fuji and repeatedly blasts Mothra aside with his gravity beams. Godzilla and Rodan are inspired by the larva's courage, and decide to help her battle King Ghidorah.

As the Earth monsters struggle against the space demon, Shindo notices that the prophetess has wandered off and is standing over a gorge, praying. Malmess climbs to the top of the other side of the gorge and opens fire on the prophetess with a sniper rifle. One shot grazes her head and causes her to fall onto another ledge. Shindo jumps down to help her, and finds that she has returned to her right mind and now knows she is actually Princess Salno. As Malmess opens fire on her and Shindo, the princess recognizes Malmess and calls him a traitor. Just before Malmess can kill either of them, one of King Ghidorah's stray gravity beams strikes the mountainside, causing an avalanche that sends Malmess plummeting to his death in the gorge below. Tsukamoto and the others help Shindo and the princess to safety, while the Earth monsters gain the upper hand against King Ghidorah. When Mothra covers King Ghidorah in silk, Godzilla grabs him and throws him off a cliff, after which he begins pelting him with boulders. Finally, King Ghidorah takes flight and flees into space, while Godzilla, Rodan and Mothra look on.

Sometime later, Shindo, Tsukamoto, Naoko and Murai are present at the airport to bid farewell to the princess before she departs for Selgina. The princess asks Tsukamoto how she regained her consciousness, to which he replies it was the shock from being shot in the head. When she asks if her psychic abilities will ever return, Tsukamoto tells her it's impossible to tell. Just before she leaves, Princess Salno approaches Shindo and thanks him for saving her life three times. She says that the only things she can remember from when she thought she was a Venusian are the times when Shindo saved her. She assures Shindo that she will never forget him, then leaves in a plane. Elsewhere, Godzilla and Rodan watch from afar as Mothra and the Shobjin swim back to Infant Island.