Record company intern Aaron Green (Jonah Hill) has been given a career-making assignment. His mission: Fly to London and escort rock god Aldous Snow (Russell Brand), now a drunken disaster, to L.A.'s world famous Greek Theatre for the first-stop on a huge comeback tour. As the countdown to the concert begins, Aaron must navigate a minefield of London drug smuggles, New York City brawls and Vegas lap dances to deliver his charge safe and, sort of, sound. He may have to coax, lie to, enable and party with Aldous, but Aaron will get him to the Greek.