"Boston Strong" may have been the slogan that city needed in the wake of the 2013 Boston Marathon bombing. But slogans mean nothing in the face of life-changing trauma, an idea that vibrates through Jake Gyllenhaal's agile, unnerving performance in David Gordon Green's Stronger. Gyllenhaal plays Jeff Bauman, a real-life marathon spectator who lost both legs in the attack. The day he shows up to watch his ex-girlfriend cross the finish line (she's played, with steel-spined grace, by Tatiana Maslany) becomes the day that forever changes his notion of what it means to step up to the plate, for himself or for anyone else.
Green's film has a tense, nervy energy, most of which seems to glow from Gyllenhaal's very core. In one scene, his anguished, hesitant cries give us a sense of how painful it is after an amputation to have your dressings removed. There's both wildness and weakness in him, an unruly combination that we usually call courage, only because we don't have a better word for it.