The story is set in the working-class neighborhood of Mystic River in Boston. It revolves around three childhood friends: Jimmy Markum (played by Sean Penn), Sean Devine (played by Kevin Bacon), and Dave Boyle (played by Tim Robbins).
The film opens with a flashback to 1975 when the three boys are playing hockey in the street. Dave is abducted by two men posing as police officers and sexually abused for several days before escaping. The traumatic event deeply affects the boys and sets the course for their lives.
Flash forward to the present day, and the three men have grown apart but are brought back together by a new tragedy. Jimmy’s 19-year-old daughter, Katie (played by Emmy Rossum), is found brutally murdered. Sean, now a detective with the Massachusetts State Police, is assigned to investigate the case.
As Sean delves into the investigation, tensions rise between Jimmy, a former criminal turned grocery store owner, and Dave, who is now a troubled and socially awkward man. Suspicions and accusations abound, with Jimmy seeking vengeance and Dave haunted by his past.
In the climax of the film, Sean discovers evidence implicating Dave in Katie’s murder. Convinced of his guilt, Jimmy takes matters into his own hands and confronts Dave at gunpoint. However, Dave reveals the truth about his past and his innocence in Katie’s murder.
In a shocking twist, it is revealed that another man, Brendan Harris, was the true killer. Brendan, driven by jealousy and rage, mistakenly believed Katie had rejected him and killed her in a fit of rage. Sean apprehends Brendan, and justice is served.
In the aftermath, the three men grapple with the consequences of the tragedy and the choices they’ve made in life. Dave struggles to come to terms with his past trauma, Jimmy mourns the loss of his daughter, and Sean reflects on the fragility of life and the bonds of friendship.
“Mystic River” is a powerful and emotionally resonant film that explores themes of grief, guilt, and redemption. With its compelling storyline, complex characters, and stellar performances, the movie is a gripping and thought-provoking examination of the human condition.