Jeff Bauman is a kind-hearted yet struggling individual from Boston who works the deli counter at a Costco, sharing a cramped two-bedroom apartment with his alcoholic mother, Patty. At a local bar one evening, Jeff encounters his ex-girlfriend, Erin, who is drawn to his kindness but is exasperated by his reluctance to commit. After learning that Erin plans to run in the 2013 Boston Marathon to fundraise for her hospital job, Jeff makes an effort to rally support from everyone present in the bar to donate. He then vows to Erin that he’ll hold a big sign for her at the finish line.
On the day of the Marathon, Jeff hastily makes his way to the finish line, where he arrives before Erin. Tragically, as she nears the finish line, a bomb detonates right where Jeff is standing. Following the explosion, he is rushed to the hospital, where he undergoes surgery that results in both of his legs being amputated above the knee. Upon awakening, Jeff tells his brother that he spotted the bomber prior to the blast, leading Patty to contact the FBI. Jeff’s description of Tamerlan Tsarnaev aids law enforcement, and the subsequent capture of Dzhokhar Tsarnaev marks Jeff as a local hero.
Adapting to his new circumstances proves challenging for Jeff as he grapples with his sudden fame. Patty arranges multiple media interviews, surrounding him with reporters during his rehabilitation, while Erin, who has reignited her relationship with Jeff, expresses her discontent with the incessant media attention. An invitation from the Boston Bruins to attend Game 2 of the Stanley Cup Playoffs further complicates Jeff's mental state. During the game, as he waves a flag in a stadium filled with cheering fans, he experiences flashbacks of the traumatic event, leading him to break down in an elevator. Erin provides comfort and insists that he discuss his mental health with his family, recognizing the strain his newfound notoriety places on him. They share an intimate moment that night, expressing their love for one another.
However, complications arise when Patty schedules an interview with Oprah Winfrey without consulting Jeff, provoking Erin to confront her about the detrimental impact of the media on Jeff's PTSD. A heated argument ensues, revealing Jeff’s reluctance to continue participating in interviews. Patty voices her desire for the world to recognize how exceptional her son is, but her actions inadvertently encourage Jeff's unhealthy habits, such as his drinking and neglecting rehab appointments. Erin, who has moved in with Jeff, finds herself exasperated by Patty’s behavior and Jeff’s passivity, ultimately leading her to confront both of them.
While out drinking with his brothers one night, Jeff engages in a bar fight triggered by patrons insinuating the bombing was a conspiracy. Later, Erin reveals she is pregnant, causing Jeff to panic and express his unpreparedness for fatherhood, which results in her leaving in distress. As she packs her belongings later in their apartment, Jeff experiences a vivid PTSD flashback of the bombing.
In a chance encounter, Jeff meets Carlos, a man who played a pivotal role in his survival after the bombing. Carlos shares his painful history, including the death of his sons, and how saving Jeff helped him heal emotionally. This encounter inspires Jeff to confront his own desire to live and support others, prompting him to quit drinking and commit seriously to his rehabilitation. He calls Erin to apologize, finally acknowledging his previous immaturity and fear.
In a heartwarming moment, Jeff and Carlos have the honor of throwing the first pitch at a Boston Red Sox game, where Jeff meets baseball legend Pedro Martinez. After the game, he is greeted by numerous fans expressing their gratitude for his impact on their lives. The story culminates in a touching scene where Patty drops Jeff off for a date with Erin at a diner, marking a significant moment as he walks independently with his prosthetics for the first time. He tells Erin he loves her, to which she simply replies, "Good," as they share a tender moment, hand in hand, building hopes for their future together.
