Twenty years have passed since the cataclysmic invasion of 1996, and although Earth rebuilt in Independence Day: Resurgence, the scars remain not just in ruined buildings but in political mistrust and existential fear. The Earth Space Defense (ESD), formed from reverse-engineered alien tech, operates bases throughout the solar system—on the Moon, Mars, in orbital stations—and humanity has prepared for the possibility that the Harvesters or some other alien threat might return. But no one was ready for what actually happens.

A mysterious alien entity, known only as the Sphere, contacts Earth. It claims to be a member of an interstellar coalition whose home worlds are embroiled in a civil war. The war is being waged against a species—Harvesters being only one branch—who threaten to unleash total destruction beyond their own galaxy. The Sphere offers to help Earth defend itself in exchange for human participation in this broader intergalactic war, and some advanced technologies stored on a hidden refuge planet.

Meanwhile, familiar faces from past battles—scientists, military specialists, and leaders who fought in 1996 and 2016—are reunited. Among them are younger heroes, children of the old guard, now skilled pilots or strategists, who must prove themselves in ways their parents once did. David Levinson returns as a key coordinating force, working alongside Jeff Goldblum’s character and others to adapt human military capabilities into something usable in alien combat.

Humanity builds a fleet: hybrid fighters, energy-based weapons, ships capable of wormhole travel. But there are divisions—some governments distrust the Sphere’s motives, fearing that helping the alien resistance could draw destructive retaliation. Moreover, some aliens from the coalition have hidden agendas. Internal betrayal threatens to unravel the fragile alliances.

As political tensions rise, Earth is forced to send a strike force through a wormhole to the hidden world promised by the Sphere. This mission is both scientific and military: to gather arms, form bonds with resistance aliens, and foment unity. They must face alien warlords, defend against monstrous bioweapons, and confront moral questions about whether threat justifies compromise.

In a climactic battle, the combined forces of Earth and its alien allies engage the Harvesters (or the true antagonist species) on their homeworld, or at least at a staging fortress. Sacrifices are made. Some characters lay down their lives to allow others to escape. In the end, though the primary enemy is defeated or repelled, the action leaves open the possibility of more cosmic dangers: the Sphere hints that even greater perils lurk beyond the known coalition, suggesting the war is only just beginning.

The film closes with Earth more united, battle‑scarred but confident it now has a place in the larger intergalactic community. Young heroes look outward toward the stars, ready for whatever comes next.