In way over their heads to their mob patrons, Boston bare-knuckle fighter Walter "Lion" Kaminski (Jack O'Connell) and his big brother/handler Stanley (Charlie Hunnam) can make good if they drive to San Francisco for a high-stakes underground tourney-and hand-deliver a runaway teen (Jessica Barden) to the suspect care of a Reno thug (John Cullum). A road trip of revelations unwinds in this absorbing, '70s-redolent three-hander. Jonathan Majors, Fran Kranz, Meredith Holzman co-star.