John Garrity, a Scottish structural engineer, tries to reconcile with his estranged wife and prepare for a party to watch a passing comet. However, when a series of comet fragments threaten Earth, John and his family must navigate chaos, looting, and a race against time to find safety. Along the way, they encounter kidnappings, military conflicts, and desperate attempts to reach a military base for evacuation. Despite the challenges, they refuse to give up and ultimately reunite and make it to a bunker in Greenland, where they join other survivors as Earth faces global destruction.

Having found the safety of the Greenland bunker after the comet Clarke decimated the Earth, the Garrity family must now risk everything to embark on a harrowing journey across the wasteland of Europe to find a new home.