In Cooperstown, NY, August Monroe pursues his passion for baseball with his best friend Kevin Bentworth. Their bond is tested when August uncovers a mystery hidden for decades about Kevin's father and the man whose career the elder Bentworth ended prematurely. Kevin's major league success strains the friends further after August survives a career-ending injury. Years later, they reunite to share the summer of 1998 when baseball's home run record is threatened by Mark McGwire and Sammy Sosa. Multiple tragedies force them to say goodbye to their childhood forever. Between the Innings crackles with the intensity of a high fastball and serves as an ode to the sport of baseball itself.