Johnny Knoxville reprises his JACKASS role as 86-year-old Irving Zisman in the story of a crotchety old man unexpectedly saddled with the care of his 8-year-old grandson Billy (Jackson Nicoll). The two generations of troublemakers soon develop a bond, as they hustle their way across the heartland of America on an outrageous road trip with a whole lot of hijinks and pranks on unsuspecting, real-life people - all of whom had no idea they were starring in a hidden camera comedy.