Narrated by Academy Award® winner Matt Damon, the film chronicles the story of the iconic Boston Marathon--from its humble origins with only 15 runners to the present day. In addition to highlighting the event as the oldest annually contested marathon in the world, the film showcases many of the most important moments in more than a century of the race’s history. Among these monumental moments are the tragic events of 2013 and the preparations for and eventual running of the 118th Boston Marathon one year later, when runners and community gathered together once again for what would be the most meanigful race of all.