In 1976, at a Boston Police station, two policemen discuss the arrest of Fr. John Geoghan for child molestation. A high-ranking cleric talks to the mother of the victimized children. An assistant district attorney then enters the precinct and tells the policemen not to let the press learn what has happened. The arrest is not publicized and Geoghan is released.
In 2001, Marty Baron, the new managing editor of The Boston Globe, meets Walter "Robby" Robinson, the editor of the newspaper's "Spotlight" investigative team. After Baron reads a Globe article about a lawyer, Mitchell Garabedian, charging that Cardinal Bernard Law, the Archbishop of Boston, knew about Geoghan's sexual abuse of children and did nothing to stop it, Baron urges the Spotlight team to investigate. Journalist Michael Rezendes contacts Garabedian, who initially declines to be interviewed. Though he is told not to, Rezendes reveals that he is on the Spotlight team and convinces Garabedian to talk.
Initially believing that they are following the story of one priest who was moved to new assignments several times, the Spotlight team begin to uncover a pattern of sexual abuse by other priests in Massachusetts and an ongoing cover-up by the Boston Archdiocese. Through Phil Saviano, who heads the victims' rights group Survivors Network of those Abused by Priests (SNAP), the team is led to widen their search to thirteen priests. Richard Sipe, a former priest who worked to rehabilitate sexually abusive priests, tells them that his studies suggest that there are approximately 90 abusive priests in Boston (6% of priests). Through their research, the team develops a list of 87 names and begin to find victims to back up their suspicions.
As the team realizes the sheer scale of the investigation, it begins to take a toll on their lives: reporter Matt Carroll learns one of the priest rehabilitation centers is on the same block as his family's home but cannot tell his children or his neighbors to avoid spoiling the story; reporter Sacha Pfeiffer finds herself unable to attend church with her grandmother; Rezendes pushes to get the story out quickly to prevent further abuse; and Robinson faces pushback from some of his close friends who he learns were complicit in covering up the abuse.
When the September 11 attacks occur, the team is forced to de-prioritize the story. They regain momentum when Rezendes learns from Garabedian that there are publicly available documents that confirm Cardinal Law was made aware of the abuse and ignored it. Although Rezendes argues vociferously to run the story immediately, before more victims suffer and rival newspapers publish comparable articles, Robinson steadfastly refuses, arguing the team needs to research further so that the systemic problem can be more fully exposed. After the Globe wins a case to have even more legal documents unsealed that provide the evidence of that larger picture, the Spotlight team finally begins to write the story and plan to publish their findings in early 2002.
As they are about to go to print, Robinson admits that he learned during the investigation that he was sent a list of 20 sexually abusive priests by lawyer Eric MacLeish in 1993, on which Robinson never followed up. Baron still commends Robinson and the Spotlight team's efforts to expose the crimes now. The story goes to print with a weblink to the documents that expose Law's inaction and a phone number for victims of abusive priests. The next morning, the team is inundated with calls from victims coming forward to tell their stories.
A textual epilogue notes that Law resigned in December 2002 and was eventually promoted to the Basilica di Santa Maria Maggiore in Rome, and presents a list of 105 U.S. communities and 101 others around the world where major scandals involving abuse by priests have taken place.
