During the 1972 Summer Olympics in Munich, the ABC Sports crew presides over what appears to be a spirited and relatively uneventful Games coverage. When Mark Spitz wins gold in the swimming event over a West German competitor, ABC Sports president Roone Arledge, Peter Sarsgaard, dramatizes the moment by cutting to the rival's reaction and planning to introduce the subjects of the Holocaust and Nazi Germany during a live interview with the Jewish Spitz. When Marvin Bader, Ben Chaplin, head of operations, questions the decision, Arledge reminds him of the importance of emphasizing emotions over politics to make an effective broadcast.
During the night, gunshots are heard in the distance. The crew listens to police broadcasts, aided by Marianne Gebhardt, Leonie Benesch, the crew's local translator, and gradually learn that a terrorist attack is occurring: The terrorist group Black September has broken into the apartment housing the Israeli team and taken the athletes hostage, demanding the release of hundreds of Palestinian terrorist prisoners. Seeing an opportunity for a compelling story, Geoffrey Mason, John Magaro, the head of the control room, quickly organizes the crew to pivot to cover the hostage crisis instead. Along with Arledge, he takes pragmatic steps to turn the story into a gripping sensation, negotiating more advantageous time slots and even forging identification so that a crewmember can access the now-restricted Olympic village. Although most of the crew is enthusiastic and confident that the conflict will be resolved quickly and successfully, a dismayed Bader reminds Mason and Arledge that the lives of real people are at stake and warns them of the potential impact on the terrorists' narrative.
Throughout the day, the crisis worsens due to failed negotiations and mistakes from an unprepared local police force. Countless news stations jockey for the latest news and glimpses of the standoff, inciting Mason to become more competitive in covering the story. At one point, the crew realizes that the terrorists are watching their program, which ruins an attempted rescue. Law enforcement officers storm the control room and threaten the crew at gunpoint to turn off the broadcast, but Mason ultimately refuses. The terrorists are eventually transported with their hostages to the military airport of Fürstenfeldbruck, and Mason sends Marianne there for coverage, cynically including sound equipment in case a shootout takes place.
Marianne, at the airport with other news crews, reports to Mason that the hostages are rumored to be free, which is apparently confirmed by ZDF. Bader implores Mason to hold off on reporting until the information is confirmed, as the other stations will follow suit, but Mason is unwilling to lose the scoop and has the news announced, albeit with the caveat that the station qualifies its report by stating that the unconfirmed developments are what is currently being reported from its sources. Bader is furious but is pacified when Mason soon receives an official fax from German chancellor confirming the group's rescue. As the crew celebrates and Mason pivots to planning interviews with the survivors, Bader leaves to celebrate with Arledge. As he watches a live, televised ABC interview with Conrad Ahlers, acting as a spokesperson for the German government, Ahlers speaks of the resolution to the crisis in an optimistic future tense. Realizing that the reports the studio received were all incorrect, a horrified Bader contacts an inside source and learns that the rescue attempt failed and all the hostages were in fact murdered.
Sobered, Mason has Jim McKay correct the live broadcast. Arledge nevertheless commends him for an excellent job, while Marianne mourns that yet more innocent lives were lost on German soil, and she and countless other reporters had been at the airport, focused only on getting a scoop while lives were being lost. The crew heads home, and after closing up, Mason lingers to view the studio's bulletin board featuring photos of the victims.
A closing title card reveals that the event was the first time a terrorist attack had been broadcast on live television and was viewed by an audience of approximately 900 million, making it one of the most viewed broadcasts in history.