Peter Highman (Robert Downey Jr) has received word that his baby is due to be born, he’s about to be a father for the first time, the only problem is he is in Atlanta... and his baby is being born in Los Angeles.
Travelling home is his only option, but his wallet and luggage are stolen leaving him stranded and desperate and with nowhere to go! That is until kind stranger Ethan Tremblay (Zach Galifianakis) offers Highman a ride home, this decent act seems like a miracle for Highman, but little does he know what he’s in for.
Tremblay is not what most people would describe as an average guy; he’s an aspiring actor and is quite frankly a little bit insane. Together they’re on a road trip from hell, action and adventure ensue along with a splashing of insanely funny comedy.