Henry 'Razor' Sharp and Billy 'The Kid' McDonnen are old boxing rivals who come out of retirement for one final match. On their first encounter in decades, their long-festering feud erupts into an unintentionally hilarious melee that instantly goes viral. The sudden social media frenzy transforms their local grudge match into a must-see HBO event. Now, if they can just survive the training, they may actually live to fight again.