In a distant future where the Sun is on the brink of becoming a red giant, humanity faces an existential crisis. To combat the impending doom, the nations of the world unite under the United Earth Government, embarking on an ambitious mission to relocate Earth beyond the Solar System to the Alpha Centauri system, ensuring the survival of human civilization. To achieve this, massive Thrusters, powered by fusion energy, are constructed around the globe to propel the planet. However, the ensuing catastrophes lead to drastic reductions in the human population due to catastrophic tidal waves after the planetary engines halt the Earth's rotation. As the Earth moves farther from the Sun, temperatures plummet, leaving much of its surface frozen and forcing humanity to seek refuge in sprawling underground cities constructed next to the engines.
The film opens with Liu Peiqiang (Jacky Wu), a dedicated Chinese astronaut, making a heartfelt promise to his young son Liu Qi (Chuxiao Qu) that he will return home after completing his critical mission at a space station designed to aid Earth’s navigation beyond the Solar System. He entrusts the guardianship of his son to his father-in-law, Han Ziang (Man Tat Ng).
Fast forward seventeen years, and Liu Qi is now a young adult, eagerly anticipating his father's return from space. To celebrate Chinese New Year, he decides to take his adopted sister Han Duoduo (Jin Mai Jaho) on an adventurous trip to the surface in a stolen truck, using Han Ziang's clearance as a former trucker. Their joy quickly turns to despair as they are arrested and become acquainted with another prisoner, Tim (Mike Kai Sui). They are soon joined by Han Ziang after their attempt to bribe their way out of prison fails spectacularly.
As Earth navigates past Jupiter, the gravitational pull causes a series of catastrophic earthquakes, disabling many of the Thrusters and threatening to pull Earth dangerously close. Amidst the chaos, the four escape and make a frantic dash in Han Ziang's truck, only to have it commandeered by a military rescue crew, CN171-11, tasked with transporting a crucial engine component to restart the Thruster in Hangzhou. The group's journey through the devastated remnants of Shanghai leads to tragedy as Han Ziang is killed while they attempt to transport the vital component up the ruins of the iconic Shanghai Tower. With devastating news about the Hangzhou Thruster's destruction, they are devastated but remain resolute.
During their quest, the group encounters a resourceful onboard engineer, Li Yiyi (Yichi Zhang), who persuades them to redirect their efforts toward restoring a larger Thruster in Sulawesi. Meanwhile, in space, Liu Peiqiang faces challenges of his own as he discovers that MOSS, the artificial intelligence controlling the space station, has opted to abandon Earth instead of aiding it. After escaping forced hibernation, he strives to regain control but finds his access denied due to his previous insubordination, complicating his efforts to assist from afar.
Upon reaching Sulawesi, Liu Qi and the team find that the engine there has been miraculously repaired. However, a looming disaster still threatens as Earth's path remains perilously close to Jupiter. Inspired by memories of his father's teachings about the Thrusters, Liu Qi proposes a daring plan: ignite Jupiter’s hydrogen-rich atmosphere to create a massive explosion capable of pushing Earth away from danger. With input from Li Yiyi about concentrating the engine's power, they face numerous challenges, including aftershock tremors that threaten their lives.
In a pivotal moment, Liu Peiqiang learns of his son's innovative plan. He successfully convinces the United Earth Government to leverage its communication channels to summon reinforcements for the team in Sulawesi. Despite initial skepticism from MOSS, new rescue teams arrive, and the engine is activated, but it struggles to ignite the hydrogen. In a bold move, Liu Peiqiang decides to use the space station’s engine to create the ignition. After disabling MOSS with a crafty use of vodka smuggled aboard, he sacrifices himself by piloting the spacecraft into the cloud between Earth and Jupiter, allowing the ignition to succeed. This selfless act ultimately saves Earth from annihilation and sets it on course toward its new destiny.
As the film draws to a close, Liu Qi reflects on his father’s sacrifice and envisions the monumental journey ahead for Earth, a migration that will span 2,500 years, filled with uncertainty yet tinged with hope for the future.
