Two boys, Ellis and his best friend Neckbone, find a mysterious man named Mud hiding out on a deserted island in the Mississippi. Mud tells the boys fantastic stories about his life, including how he killed a man in Texas and vengeful bounty hunters are coming to get him. He says he is planning to meet and escape with the love of his life, Juniper. The boys agree to help him, but it isn't long until their small town is besieged by bounty hunters out for blood.