Jackson Curtis (JOHN CUSACK) is a barely published Los Angeles author who's separated from his wife, Kate (AMANDA PEET), and has essentially been replaced in the eyes of their kids -- 7-year-old Lilly (MORGAN LILY) and her older brother Noah (LIAM JAMES) -- by Kate's breast enhancement surgeon boyfriend, Gordon Silberman (THOMAS McCARTHY).
To make ends meet, Jackson is a limo driver for the rich, such as Russian billionaire Yuri Karpov (ZLATKO BURIC), his two bratty sons, and the man's trophy girlfriend, Tamara (BEATRICE ROSEN), driving them to the airport where they'll be flown off by Russian pilot Sasha (JOHANN URB).
When his own car won't start, Jackson uses the limo to take his kids camping in Yellowstone where they end up trespassing on newly prohibited government controlled land. That results in them being taken into custody by the U.S. military where they meet geologist Adrian Helmsley (CHIWETEL EJIOFOR).
Having earlier discovered that neutrons from a massive solar flare three years earlier are super-heating the Earth's core and thus destroying its crust, Adrian now works for White House Chief of Staff Carl Anheuser (OLIVER PLATT) who's helped arrange a continuity of the species plan for President Thomas Wilson (DANNY GLOVER) and other world leaders.
All of which means the world is coming to an end, something already predicted by doomsayer radio deejay Charlie Frost (WOODY HARRELSON) who Jackson also meets, informing him of the top-secret location where enormous survival arks are being constructed by the likes of Chinese laborer Tenzin (CHIN HAN).
He's secretly planning on getting his monk brother, Nima (OSRIC CHAU), and rest of the family onboard one of them, and President Wilson's adult daughter, Laura (THANDIE NEWTON), is obviously guaranteed a seat. But it's probably not going to work out for Adrian's dad, Harry (BLU MANKUMA) -- who performs as a lounge singer on cruise ships along with Tony Delgatto (GEORGE SEGAL) -- or billions of other people.
As the crust deteriorates faster than expected, resulting in massive earthquakes, continental shifts and enormous tsunamis, Adrian and other government officials race to put their survival plan into motion, all while Jackson tries to save his family from the pending calamity.