In the summer of 1974, in the Irish suburb of South Boston, Mary Pat Fennessy leads a routine existence. One evening, Jules, her seventeen-year-old daughter, does not come home, and her trace disappears in the damp heat of the city. The same night, a young black man was fatally hit by a train in suspicious circumstances. These two seemingly unrelated events plunge the people of Southie into turmoil. Especially since the recent policy of desegregation implemented by the city is causing racial tensions and a major demonstration is being prepared. In her frantic search for her daughter, Mary Pat, who believed she belonged to a united community, finds the doors closing before her. Faced with this wall of silence, this angry woman will have to fight alone to bring out the truth, however devastating it may be.