Final Fantasy: The Spirits Within movie plot

In 2065, due to the impact of the Leo meteorite, a form of life called ghosts was produced on the earth. Ghosts can traverse any physical obstacles, they will actively attack humans and absorb human souls, and even humans can cause infection as long as they come into contact with them. The city was deserted, and humans were forced to emigrate to several "fortress cities" protected by barriers. Apart from the ghosts, there was almost no life. Dr. Sid and his assistant Dr. Archie Ross are conducting research in this area. They believe that as long as eight “souls” are found outside the fortress, they will be able to find the ghosts. The opposite waveform of the biological wave, by emitting this wave, the ghost can be wiped out. At the same time, General Hein, who hated the ghost because he killed his wife and children, insisted on using the Zeus cannon to attack the meteorite. But the doctors thought that doing so would harm the soul of the earth "Gaia", and later they realized that these ghosts are actually the souls of dead creatures on the planet after the destruction of the planet where the meteorite is located, and they are not alien invaders. But General Hein's paranoia made him crazy and even caused him to destroy New York City with his own hands. Just as the brave captain Gray and Aqi found the eighth soul in the crater, Hein gave the Zeus cannon to launch the crater. The Gaia on the earth was attacked and damaged, and the alien Gaia spread rapidly. The Zeus cannon was also wiped out due to overload due to frequent firings of Heyin. But in the end, Aqi saved the world and purified the alien Gaia with the wavelength remaining in the body, but Gray was taken away by the alien Gaia as a purification conductor. A new day is ushered in on the earth, and Aqi looks at the rising sun of hope slowly while holding her dead lover.