Five years have passed since the Clarke comet struck Earth, wiping out over 75% of humanity. Survivors have relocated to bunkers, living under the constant hum of emergency protocols as electromagnetic storms crackle across the sky. John Garrity, [Gerard Butler], is a resourceful scout and engineer who patrols the wastelands between shelters, while Allison Garrity, [Morena Baccarin], works with a bunker council to manage life underground and oversee the survivors on the outside.
In the claustrophobic confines of the bunker, Nathan, [Roman Griffin Davis], a student, becomes a poignant symbol of the young generation caught between fear and curiosity as he tries to leave the safety of the underground, only to be caught by his worried parents. John narrowly escapes an overwhelming electromagnetic storm and makes it back inside, but the danger outside never fully recedes, a constant reminder of how fragile life has become.
With tremors and shifting radiations threatening every plan, the council discusses moving toward the Clarke impact crater in southern France, a place that was once the Gulf of Lion and the Mediterranean Sea and where humanity now hopes to rebuild. The journey would be perilous, traversing war zones filled with insurgents and marauders who prey on the desperate. Amid this backdrop, John has contracted a radiation-related illness that slowly drains his strength and will to live, a truth he hides from Allison and Nathan as the clock ticks down.
Allison pushes for a rescue mission to pull survivors from the outskirts, hoping to salvage lives even as the bunker debates how to respond. When a return from the exterior party reveals little, the residents decide to press on, but a massive earthquake forces everyone to evacuate their shelter. The Garritys secure a place on a large lifeboat just as a colossal tsunami obliterates the facility and everything that stood beyond.
The boat washes up on the shores of Liverpool, and survivors push toward a gate into another bunker. They are admitted with badges, yet chaos erupts when a companion loses his and tries to force entry, ending in his shooting. In the ensuing mayhem, the Garritys flee with Dr. Amina, [Amber Rose Revah], toward a caravan driven by Obi, a Nigerian driver who helps them move forward through a landscape that has grown even more hostile.
Their route takes them into the woods for a rest, but a meteor cluster forces them to cling to trees as rocks rain down. Obi is killed while trying to save his van, and the group presses on toward safer ground. They eventually reach the London home of Mackenzie, [Sophie Thompson], for shelter and food, where Allison learns of John’s worsening condition—he now has perhaps six to eight weeks left—and the decision to press on splits the family between staying put and chasing the possibility of a better future.
After leaving Mackenzie’s, they face marauders again, and Amina is killed in the skirmish. John defends his family, neutralizing the attackers but taking a devastating wound to his abdomen. They bury Amina and press onward toward the English Channel, which has dried up into a perilous, exposed crossing. To reach the Clarke crater, they join another group of travelers who must cross a treacherous chasm over unstable bridges; fierce winds hurl some travelers to their deaths, but the Garritys persevere and cross together.
In Calais, they encounter Denis Laurent, [William Abadie], who welcomes them into his home and introduces them to his wheelchair-bound wife Julia and their daughter Camille. Camille, who catches Nathan’s eye, joins the group after bidding her parents farewell. With the front lines of a war zone ahead, Denis arranges contact with Commander Jeunet to help them traverse the final stretch, though Jeunet has already fallen. Undeterred, John pleads with the head soldier to allow passage across the battlefield, reminding everyone of the stakes.
They reach a transport bus filled with other survivors, but insurgents halt them, ordering everyone off. John is the last one out, fights the gunmen, and sustains a wound as he protects his family. The trio pushes toward the crater’s edge, where a shimmering oasis hints at salvation, but John collapses. Allison and Nathan carry him as they reach the crater, and John’s last moments are filled with a quiet, paternal farewell. His final narration to Nathan frames the world beyond the catastrophe as a beacon of hope for a better future, a testament to resilience even as one life ends.
