Japan D.O.E. Agent, Tetsuya Terasaki, having just completed a difficult hunt for a fugitive alien, is ordered to investigate a local alien disturbance. Expecting resistance, he has his SPECTER armor sent to him. Arriving at the site, he finds aliens torturing two scientists, trying to extract information from them. He fights off the aliens and powers down to make a report to Command.
While Terasaki checks in with headquarters, one of the scientists accidentally activates a device on the dead alien. The device resurrects the alien and enhance its powers. He kills one scientist and kidnaps the other. Tetsuya chases after them as the alien takes the scientist down into tunnel and towards his spaceship. Tetsuya follows the pair and recovers the scientist. The alien no longer needs the hostage, though, as he has his ship to eliminate Tetsuya. Tetsuya attempts to destroy the ship with his guns, but it's too well armed.
The D.O.E. commander sends down a particle cannon to help Tetsuya win. After Tetsuya fires it, he grabs the scientists and they make their way to the surface out of the tunnel, when suddenly Tetsuya realizes the alien is still alive. He shoots the alien one more time and gets the scientist to safety. Once back in civilization, the scientist demands an explanation for everything, but Tetsuya erases her memories. Afterwards Tetsuya travels home for a well-deserved rest, despite an alien "crab" attacking the US. His commander tells him to let the US Division handle it.