Academy Award winner Alex Gibney (Taxi to the Dark Side) explores the rough and tumble world of hockey.

Chris “Knuckles” Nilan can chart his hockey career by his scars. He earned those stripes as one the NHL’s fiercest enforcers, throwing punches to defend his teammates. While playing for the Montreal Canadiens in the mid-1980s, his fights racked up penalty minutes, but received roaring approval from fans and helped win the Stanley Cup. When injuries forced Knuckles to retire in 1992, he faced a new battle: how do you stop being a gladiator and re-enter normal society?