An action-packed thriller, starring JK Simmons, Scott Caan and Frank Grillo, ONE DAY AS A LION follows the painstaking lengths a man will go to, to save his loved ones. Down on his luck, Jackie Powers (Scott Caan) will stop at nothing to prevent his son from following him into a life of crime. With his mob employer in pursuit, a chance encounter at a roadside diner charts a new path.