Peter Highman (Robert Downey Jr.) must get to LA in five days to be at the birth of his firstborn. He is about to fly home from Atlanta when his luggage and wallet are stolen, and he is put on the "no-fly" list. Desperate to get home Peter is forced to accept the offer of Ethan Tremblay (Zach Galifianakis) to hitch a ride with him cross-country. Peter is about to go on a terrifying and agonizing journey of his life.