[7] In 2055,[8] wars have ravaged the Earth due to the prevalent use of advanced military robots, and global warming and pollution have destroyed the environment and ruined the atmosphere.
As a result, many people are born with birth defects and die, and large domes known as Skynets are built to protect the surviving cities on Earth.
During the construction of the Skynet over B-16 (a futuristic Hong Kong), a meteor lands in the city and a giant alien plant, later named Pandora, emerges and causes devastation to the area around it as it takes root.
Pandora grows rapidly when there is rain, taking over more of the city every time it does so; however, it is discovered that the plant can also purify the polluted air.
ASU's (a local military force) lead scientist, Dr Chan, finds a way to alter the plant's genome to stop Pandora from growing further while also letting it continue to repair the atmosphere.
Tyler and his friend Johnson Cheng, soldiers working for the ASU, are tasked with locating Pandora's pistil and delivering a "gene bullet" virus that will neutralize its growth.
Colonel Tam is sent to oversee the operation, but she has a backup plan to bomb Pandora from the air, which would destroy the plant but could potentially kill a hundred and sixty thousand people in the surrounding area.
Cheng heavily opposes the idea of sacrificing civilians and losing their best chance to fix the atmosphere, and launches the mission before two rainstorms hit the city.
Privates Connor and Lincoln join Tyler on the mission as they escort the Orca transport aircraft carrying the gene bullet virus into the operation area.
During the mission, Sean Li, the commander in chief of B-16 and the architect of the Skynet project, sabotages the Orca by remotely taking control of its complement of military robots as soon as the first storm hits, and it crashes into a building.
Damaged by Pandora's tendrils, Tyler's aircraft crashes after locating the area where the pistil is, and Lincoln is left critically injured.
Cheng, arriving in an armoured car driven by former-squad mate Skunk, uses a hatchet to kill most of the mantis-like creatures while Tyler rescues Connor.
The survivors escape the hospital and head to the building where the Orca crashed, finding the last intact gene bullet capsule and evidence that Li had sabotaged the mission in order to allow Pandora to be destroyed and the construction of his Skynets to continue.
The others arrive at the location where the pistil is and encounter a large crab-like robot, with its pulse weapon destroying the armoured car.
Afterwards, with the state of the atmosphere greatly improving, Tyler accepts a mission on the moon while Skunk and Cheng finish rebuilding the armoured car.
Aside from Koo, the cast also includes Sean Lau and Philip Keung, alongside newcomer actors Kevin Chu, Ng Siu-hin and Tony Wu.
On 10 December 2021, One Cool Pictures released a promotional clip featuring former TVB News anchor Vince Ng in a mock news clip reporting a meteorite is approaching the Earth and is projected to hit the Hong Kong at 8 PM on 17 December 2021, which was when a new trailer for the film premiered on billboard screens throughout Hong Kong before being available on the internet, displaying a slated release year of 2022.