A family struggles for survival in the face of a cataclysmic natural disaster.
A family fights for survival as a planet-killing comet races to Earth. John Garrity (Gerard Butler), his estranged wife Allison (Morena Baccarin), and young son Nathan make a perilous journey to their only hope for sanctuary. Amid terrifying news accounts of cities around the world being leveled by the comet's fragments, the Garritys experience the best and worst in humanity while they battle the increasing panic and lawlessness surrounding them. As the countdown to global apocalypse approaches zero, their incredible trek culminates in a desperate and last-minute flight to a possible safe haven.
John Garrity, his estranged wife and their young son embark on a perilous journey to find sanctuary as a planet-killing comet hurtles toward Earth. Amid terrifying accounts of cities getting level-led, the Garrity's experience the best and worst in humanity. As the countdown to the global apocalypse approaches zero, their incredible trek culminates in a desperate and last-minute flight to a possible safe haven.
- John Garrity is a Scottish structural engineer living in Atlanta, Georgia, with his estranged wife, Allison, and their diabetic son, Nathan. He returns home from work to reconcile with his family and prepare to host a party with their neighbors to watch the passing of a recently-discovered interstellar comet, named Clarke.
Arriving at a grocery store, John and Nathan notice a fleet of military cargo transport jets flying north in formation, much to their bewilderment. In the store, John receives a strange automated phone call, informing him that he and his family have been pre-selected for emergency sheltering. Worried by this, John rushes home to the party, just as a comet fragment enters the atmosphere on live television. A shock wave rattles the area and blows out windows as the fragment, previously anticipated to land near Bermuda, vaporizes Tampa, Florida, and most of the state around it. John once again receives an automated call, which also displays on the television in front of his family and neighbors with instructions to be at Robins Air Force Base to make an evacuation flight. Terrified, their neighbors storm out of the house to be close with their families while the Garritys rush to pack up and leave. Before they can, their neighbor, Ed, warns them that Clarke is actually a giant cluster of objects that are expected to bombard Earth over the next two days, with the biggest fragment expected to cause an extinction level event. Debra, another one of their neighbors, desperately begs to leave their daughter Ellie with the Garritys to be saved, but John speeds off, knowing she would be turned away.
At Robins, a line of traffic prevents the family from reaching the gate and forces them to continue on foot, with Nathan accidentally leaving his insulin in the car. They are allowed in with the QR code on John's phone and their wristbands. When forced to consolidate their belongings into one bag, they also discover that Nathan's insulin is missing. John hurries back to the car to find it while Allison and Nathan wait to board the plane, who are escorted away once a soldier learns of Nathan's ailment. Allison begs for them to be let on the plane, but is unsuccessful, and the two are escorted off the base. Oblivious to this, John makes it back to the plane in time, where another passenger confronts him about the medicine and learns that his family was turned away, too. John demands to be let off the plane just as the base is breached by an angry mob wanting to be saved. A gunfight breaks out, inadvertently blowing up many of the evacuation planes and killing dozens while John narrowly escapes.
Upon returning to their car, he finds a note left by Allison that she and Nathan are heading to her father's house in Lexington, Kentucky. After narrowly escaping a store being looted, Allison and Nathan are picked up by couple Ralph and Judy Vento, who are also headed that way. Ralph tells them they will take them as far as Knoxville, Tennessee. Meanwhile, John is walking on foot through a small city, where looting is taking place in masses as worldwide panic ensues as an approaching Clarke looms ominously in the night sky. He comes across a rooftop party and attempts to call Allison. He briefly gets through to her before the call is dropped.
Through conversation, Ralph and Judy find out that Allison and Nathan were selected for evacuation but denied entry. Ralph pulls over to kick Allison out, as well as take her wristband and kidnap Nathan, much to Judy's protest. John manages to hitch a ride on a truck with other survivors, where he learns through a young man named Colin that the military is flying to bunkers in Greenland for refuge. Another survivor, noticing John's wristband and believing only American-born citizens should have been selected, attempts to fight him for it. The ensuing chaos results in the truck nearly crashing, which kills Colin, and the hostile man is gruesomely killed by John. Meanwhile, Ralph, Judy, and a frightened Nathan later arrive at a FEMA camp where they attempt to pass as Nathan's parents to guarantee their safety as well, but they are detained when Nathan tells a soldier that he was kidnapped. Allison eventually ends up at the same camp, where a man helps her look for Nathan, and the two are reunited.
The following day, John wanders through an empty neighborhood and breaks into a house to find food and water. He turns on a TV to see various news channels reporting the worldwide destruction and a countdown to the final impact. He steals a car and finally reaches the home of his father-in-law, Dale, but realizes that his family is not there. Allison and Nathan soon get off at a small shop nearby and call the house, and are picked up by John and Dale. They return to his house, defeated and accepting their fate to die in the impact in less than a day. However, recalling some information from Colin, John realizes they might have enough time to make a last-minute flight in Canada to reach the bunkers. The family agrees to leave, saying goodbye to Dale before continuing in his truck.
They reach Upstate New York when an emergency alert warns them of molten debris threatening the region. Small fireballs rain from the sky, destroying cars, people, and downing a helicopter as people scramble to escape. John manages to drive them to an underpass for refuge, and after some time, the meteor shower ceases, leaving much of the area on fire, but allowing the family to continue to Canada as it is revealed that Clarke's largest fragment will make impact somewhere in Western Europe. John drives onto the runway as the plane is about to take off, and an angered pilot confronts the family. He argues that the plane is full and cannot take any more passengers but later agrees to take only Nathan and Allison, with the latter eventually convincing the pilot to take all of them.
The plane approaches Greenland, however, another fragment strikes off the coast, and the subsequent shock wave causes the plane to crash land into a valley, killing the pilots. After John leads his family and the survivors to the nearby airbase, the group embrace as Clarke enters the atmosphere and impacts. Nine months later, the Greenland base attempts to make radio contact with other potential survivors as various cities (Sydney, Paris, Mexico City, and Chicago) are shown in total ruin. The bunker doors open, allowing the Garritys and other survivors to step outside for the first time to see a radically changed landscape. The crowds cheer with joy upon seeing a pair of birds flying around as they exit the base. An orbital view reveals a massive crater where Clarke impacted and several smaller craters dotting the planet's surface reminiscent of the Moon as Greenland finally makes contact with other stations around the globe, who each are relieved to hear each other and report that the atmosphere is finally clearing.