GODZILLA VS THE SPACE MONSTERS EARTH DEFENSE DIRECTIVE
An airplane, on route to Haneda Airport, is suddenly struck by a strange hailstorm, causing all of the instrumentation on the plane to go out of control. The hailstorm is followed shortly by the appearance of a space monster, Gigan, whose arrival alarms the nearby crew of the airplane. As quickly as he appeared, Gigan departs as the hailstorm dissipates.
Later that evening, Okamoto, the airplane's copilot, goes to Science Land and makes his way to the Science Center, located atop Godzilla Tower, hoping to be able to investigate the strange events which he experienced earlier that morning. Upon entering the control room at 1:00am, Okamoto is startled when he receives a call in the Science Center, as he didn't notify anyone of his whereabouts. Answering the call, Okamoto hears a strange voice: "I know you are there... I can answer all your questions." Okamoto becomes curious, and asks who it's that he is speaking with, but the voice continues: "I caused everything which you saw today. The monster which you saw is under my control, and I shall take control of the skies over Japan from this time forward. My name is Alien Miko. Ha, ha, ha!" Okamoto sits in stunned disbelief at the threat. "You can't believe it? You will see!" the voice declares as it's abruptly cut off.
A few days later, a strange object is spotted over the ocean through radar; the Self Defense Force acts, and deploys a squadron of F86F Saber Jets to investigate the location. The squadron locates the strange object, which turns out to be the monster Gigan. The jets assault the creature, but are interrupted by the arrival of a second monster, Megalon, who quickly annihilates several of the fighter jets. The surviving jets retreat, and manage to ditch their planes on a nearby island as the pilots retreat inland. Megalon follows the retreating jets, before circling the island in search of the survivors. Megalon's hunt is thwarted, however, with the arrival of Anguirus, who attacks Megalon on the beach. Anguirus quickly overpowers his foe, until Gigan arrives and the two space monsters assault the earth kaiju. After a brief fight between the three monsters, Godzilla arrives to even the odds and the two space monsters break off their attack and retreat. After the two space monsters disembark, the squadron leader of the F86F Saber Jets receives a message over his communicator: "You are the only one left alive. My name is Alien Miko. If you can't believe it, just look above you." Looking overhead, the pilot stares in disbelief at the huge form of King Ghidorah hovering overhead. The voice continues: "King Ghidorah is my horse. Now you see who is controlling the skies over Japan. Ha, ha, ha..."
Air traffic all over the world comes to a standstill as the three space monsters reign over the skies. Miko's minions are put to further use, as the three space monsters destroy the Earth's orbiting satellites. Miko then issues an ultimatum to the world: turn over control of the Earth to him, or he will cut off all gas, water, and electricity to the city of Tokyo as a first step in beating the Earth's population into submission. Miko continues stating that if the Earth does not give up soon, he will unleash the three space monsters on Tokyo.
Inside the Godzilla Tower Science Center room, technicians monitor a panel of radar screens. Suddenly, the three space monsters appear on screen, and are headed directly for Science Land. The invaders arrive at Godzilla Tower, mistaking the huge structure for the real Godzilla. The trio size up the tower, preparing for an attack, when all of a sudden a roar comes from behind them as the real Godzilla has arrived to confront the space monsters. Gigan lands, and readies himself to attack Godzilla, but mysteriously the creature instead turns around and the three space monsters retreat from Science Land.
Later, King Ghidorah, Gigan and Megalon appear in Tokyo and Miko proclaims that his minions will first take over Tokyo before then moving on to New York and Moscow, and eventually total domination of the entire planet. While the space monsters encircle the city, the SDF deploys tanks and fighter jets that attack the invaders, but the Earth's military has no affect against the giant creatures. Shortly after the failed offensive, Anguirus arrives and a battle between the monster and Gigan ensues. Once again, Anguirus appears to quickly overwhelm his opponent before King Ghidorah and Megalon join their comrade. Again, the battle is interrupted with the arrival of Godzilla, and the three space monsters retreat once more. Meanwhile, Miko, a living brain, appears on local television sets to state that he withdrew the space monsters in order to prevent further destruction of Tokyo, and to blame the SDF and Godzilla for the damage already inflicted upon the city. Miko ends with a final warning: "Humans, obey Miko and you will live... otherwise you will die."
Thinking that his future subjects will be repulsed by his physical appearance, Miko decides to assume a less grotesque, although still intimidating, form. Miko chooses to merge with the statue of Majin Tuol, an ancient idol from the Andes Mountains, which is being kept at Science Land. The statue was found in the "Palace of the Gods" in the Andes, and, according to legend, when the mountains were destroyed and the palace disturbed, Majin Tuol's eyes would glow a blood red. It's then stated that Majin Tuol would come alive, and hurl his great sword to strike down his enemies before it returns, automatically, to his hand.
Unconcerned by the legend, Miko orders the three space monsters to attack Science Land, and the three invaders are confronted by Godzilla and Anguirus once more. A war between the five kaiju ensues, but Miko commands Gigan to cut the Majin Tuol statue in half using his buzzsaw, located on Gigan's chest, so that Miko can insert his life support machine into the idol. Gigan breaks away from the others to approach the statue and complete its task. Gigan awakens the blade on its chest and slices into the statue, which causes a trail of blood to ooze from the idol. Meanwhile, the tides have turned in the battle between the four kaiju as King Ghidorah has gained the upper hand against both Godzilla and Anguirus; the momentary victory is short lived, however, as the eyes of Majin Tuol begin to glow red and the statue transforms into a giant god. Majin Tuol unleashes its sword on the nearby Gigan, by thrusting his sword into him, mortally wounding the creature. The sword, automatically, returns to Majin Tuol's hand, as the panicked King Ghidorah flees after witnessing the defeat of its comrade. Majin Tuol again heaves its mighty sword, this time at the fleeing three-headed space monster, and manages to strike it down, out of the sky. Appearing overpowered the three invaders retreat back to space, leaving Miko unprotected, as Godzilla incinerates the alien with his atomic breath. With the evil forces vanquished, Majin Tuol returns to its original position, with a large wound remaining on its forehead left from Gigan's attack, as peace is once again restored.
After attempts to make another Hedorah movie failed, Toho begun work on a very different project with Godzilla vs. the Space Monsters: Earth Defense Directive. The script called for a total of six monsters, including the creation of three new kaiju: Gigan, Megalon, and Majin Tuol. The film was not to be though, and the idea was reworked into The Return of King Ghidorah, before that project was canned as well.
Although this particular film idea was scrapped, elements from it would be used in later Toho films, as Gigan and the Godzilla Tower would appear in the 1972 film Godzilla vs. Gigan, and Megalon would go on to star in Godzilla vs. Megalon (1973).