The movie begins on April 14, 2013, a day before the marathon. The next day, brothers Dzhokhar Tsarnaev and Tamerlan Tsarnaev detonate two bombs during the Boston Marathon, causing widespread panic. A young couple, Patrick Downes and Jessica Kensky, are injured and taken to separate hospitals, where they are both required to have their legs amputated. Steve Woolfenden, a family man, is also injured and separated from his toddler son, Leo, who is taken by the police to a safe location.