Godzilla Vs. Megaguirus - Plot

Plot

An experimental satellite-based weapon that fires miniature black holes, called the Dimension Tide, opens a wormhole through which a prehistoric dragonfly enters the present and deposits a single egg before exiting through the wormhole. A boy finds the egg and takes it with him when he moves to Tokyo. The egg starts oozing a strange liquid, so the boy throws the egg in the sewer. The egg, actually a mass of hundreds of eggs, splits up and starts growing when exposed to water, hatching into large dragonfly larva called Meganulon that come out of the sewer to feed. They flood a portion of the city and moult on the sides of buildings, becoming adult Meganula.

Meanwhile, the atomic dinosaur Godzilla appears, in search of a source of nuclear energy, despite the edict shutting down all such attractants after his three previous appearances. While Godzilla is fighting the G-Graspers (the anti-Godzilla section of the Japan Self Defense Forces) who are assisted by rebellious scientist Hajime Kudo, the swarm of Meganula are attracted in turn to Godzilla's energy, and attack him. Most Meganula are killed, but a few drain some of Godzilla's energy and return to the sewer. With the last of their strength, the Meganula inject Godzilla's energy into a huge, sleeping larva that is in a giant, pulsating cocoon. It molts and appears from the water as Megaguirus, the queen of the Meganula.

After destroying part of the city with shock waves generated by her beating wings, Megaguirus heads to the waterfront and faces Godzilla. Being territorial, Megaguirus considers the city to be her hunting ground. As they engage in a lengthy battle, she uses her speed to avoid Godzilla's attacks, but Godzilla eventually uses her speed against her. As she flies toward Godzilla, he lunges forward with his dorsal fins in her path. She flies into the fins, and one of her arms is severed.

During the battle, a special ability of Megaguirus is revealed: Having been mutated by Godzilla's energy, she can generate a blast similar to his atomic breath. She fires a huge ball of radiation, knocking Godzilla down. He gets back up, and Megaguirus goes in for the kill. She speeds forward with the stinger on her long tail lowered, trying to stab Godzilla between the eyes. In a climactic moment, Godzilla catches the stinger in his mouth. He bites down, crushing the stinger. Megaguirus rears up in pain, and Godzilla takes the chance to finally blast her with his atomic breath. She bursts into flames and Godzilla blasts her a second time and destroys her.

It is revealed that Godzilla was attracted to the energy of a secret nuclear project housed at the Science Institute, in violation of the ban, by Professor Yoshino Yoshizawa. The G-Graspers are now wanting to kill Godzilla (even though he just saved them from Megaguirus), but with the Dimension Tide falling out of orbit they are unable to get a lock on Godzilla, until the vengeful Major Kiriko Tsujimori pilots a ship called Gryphon towards Godzilla, ejecting only at the last second. The Dimension Tide is able to lock on to the craft and fires just before burning up on reentry; Godzilla vanishes and everyone celebrates. In a postlude, however, Major Tsujimori again enlists Kudo to investigate suspicious seismic activity; then in an after-credits scene, Godzilla's roar is heard again as an earthquake strikes Tokyo.