The novel opens with Katniss Everdeen, a young woman, standing in the ruins of her former home, known as District 12. Katniss, a citizen of the futuristic country of Panem, has just escaped from a ceremony called the Hunger Games, which the government of Panem puts on every year. In the Hunger Games, competitors from each of the twelve districts of Panem compete with one another until only one person is alive. Katniss has escaped from the Hunger Games arena with the help of her mentor, Haymitch Abernathy, a number of other Hunger Games competitors, and Plutarch Heavensbee, a double agent who pretended to be working for the government, but in actuality works for a secret rebel alliance dedicated to defeating the government. Haymitch was unable to free Katniss’s friend, Peeta, another Hunger Games competitor from District 12, and as a result, Peeta is in government captivity, suspected of being a rebel.
In retaliation for Katniss’s escape, President Coriolanus Snow, the leader of the government of Panem, has bombed District 12. Luckily, Katniss’s lifelong friend, Gale, was able to lead many of the people of District 12 away from their home before the bombs dropped. Gale led his people to District 13, a secret area that the government had falsely claimed to be uninhabited. Katniss, Gale, and many of the former residents of District 12 now live in District 13, which is located almost entirely below the ground.
District 13 is led by President Alma Coin, a tough, often brutal leader. Katniss, with her insubordination to the government, has inspired many of the districts of Panem to rebel. With this in mind, Coin wants Katniss to be a “mascot” for the rebellion: to travel through Panem, playing the part of the “Mockingjay,” a symbol of the movement. Katniss reluctantly agrees to be the Mockingjay, though she has a number of conditions—one of these conditions is that, after the rebels win the war, Katniss will be allowed to kill Coriolanus Snow herself. One night, Katniss watches government television and sees an interview between Peeta and Caesar Flickerman, the official TV reporter of Panem. In the interview, Peeta tells Caesar that he thinks the rebellion is suicidal, and that Katniss and all other rebels should throw down their weapons. After watching this interview, many of the rebel leaders, including Coin, want Peeta to be tried for war crimes. As another one of her conditions, Katniss ensures that Peeta will be issued a full pardon when the war is over. With this agreement set up, Katniss embarks on her duties as the Mockingjay.
Plutarch and his assistant, Fulvia, prepare Katniss to film a series of propaganda videos designed to attract people to the rebel cause. These videos are awkward and unconvincing, as Katniss struggles with her duties as a mascot. Haymitch points out the problem: Katniss is at her best when she improvising, not when she’s following a script. With this in mind, Coin sends Katniss out on missions into other districts, accompanied by Gale, Coin’s assistant, Boggs, and a large TV crew. The goal is for Katniss to encounter some real danger, show real courage, and thus inspire as many people as possible to join the rebel alliance.
Beetee, a rebel agent who competed in the Hunger Games alongside Katniss, has designed explosive arrows for her. Gale and Beetee also show Katniss a clever double bomb that they plan to use on the government soldiers.
Katniss’s first destination is District 8, where large riots are being organized against Snow’s government. There Katniss meets Commander Paylor, an important rebel leader. Paylor takes Katniss to visit rebel hospitals, where Katniss’s presence by itself is enough to console the sick and wounded. Suddenly, Paylor cries out that there is a government air raid underway. Instead of returning to safety, as Plutarch and Haymitch have instructed her to do, Katniss bravely runs out into the open, shooting explosive arrows at the fleet of government hovercrafts now bombing the hospital. Katniss successfully defends District 8 from this threat, and after the hovercrafts leave, she delivers a stirring speech about how “fire is catching.”
Back in District 13, Katniss is amazed to see her own speech broadcast throughout Panem—Beetee hijacks the government’s media network and uses it to send out the rebels’ messages. Haymitch congratulates Katniss but warns her about disobeying him again. One night Katniss is surprised to see another interview with Peeta, on a government-sponsored channel. Peeta claims that the rebels are causing mayhem, and, seeming to speak directly to Katniss, he asks her if she really trusts the rebel leaders. Even In the coming days, the rebel leaders don’t mention Peeta’s interview to Katniss at all, and even Gale doesn’t bring up Peeta. Katniss tells Gale that she saw the interview, and that she’s furious with him for not bringing up the issue when he saw her. She also wonders, privately, if her actions in District 8 haven’t caused Peeta more misery—since he’s in government captivity, it’s easy to imagine Snow torturing him more harshly as a result of Katniss’s attacks.
Katniss’s next mission is to District 12. There, the TV crew films her singing a song her father taught her, called “The Hanging Tree.” Afterwards, Katniss and Gale walk through their old community, and Gale admits that he’s in love with her. Katniss kisses Gale, but the kiss brings him little happiness—he says that Katniss only loves him when he’s in pain.
When Katniss returns to District 13, there is another interview with Peeta playing on television. In the middle of the interview, Peeta yells out that District 13 will be “dead by morning.” On television, guards seize him and beat him savagely. Haymitch realizes that Peeta was trying to warn the rebels of a government attack. Coin orders everyone in District 13 to retreat into bunkers. Katniss spends the next few days with her mother and sister, Primrose, and hears explosions above her, indicating that the government is bombing District 13. During their time in the bunker, Primrose points out that Snow will keep Peeta alive in order to weaken Katniss. Finnick Odair, another rebel and former competitor in the Hunger Games, tells Katniss that Primrose is correct: Snow likes to control his enemies by imprisoning their loved ones. His own love, Annie Cresta, he explains, is also in captivity.
Shortly thereafter, Coin announces that Gale, Boggs, and others are going on a mission to rescue Peeta from the government. Katniss is forbidden to go on this mission, since she’s too valuable to the rebel cause, a reason that Katniss finds infuriating. Only a few days after the mission leaves, it returns with both Peeta and Annie Cresta. But when Peeta sees Katniss, he tries to strangle her. Haymitch realizes that Peeta has been tortured and conditioned by the government until he believes that Katniss is the cause of all evil in Panem. Peeta must slowly be de-conditioned until he’s comfortable with Katniss once again.
Katniss’s next mission is in District 2. As she arrives there, Gale tells her that he’s not jealous of Peeta anymore—indeed, he feels sorry for him. Impulsively, Katniss kisses Gale, and they reminisce about their time in District 12. Soon after, the rebels discuss a plan to bomb the “Nut,” a large government stronghold in District 2 that nonetheless houses a large number of civilians. Gale proposes that the rebels kill civilians, reasoning that the government already blew up District 12, and thus, it’s due for a retaliatory bombing. The rebels agree to this plan, and the next day, a bomb goes off in the Nut, causing many innocent people to die. In the ensuing chaos, Katniss is shot, though her body armor protects her. She wakes up back in the District 13 hospital, and slowly begins to recover.
The next mission is to the Capitol itself, but Katniss is not invited to join it, since she needs more time to recover. Katniss begs Coin for a chance to go to the Capitol and kill Snow—reluctantly, Coin agrees, if Katniss can recover her health in the next month. Katniss goes on a strict regimen of training and exercising, undergoing a dangerous series of accelerated surgeries in the process. After a month, Katniss succeeds in qualifying for the mission. Her fellow soldiers include the camera crew, Gale, Boggs, Boggs’s subordinate, Jackson, and Finnick. Plutarch will be supervising the mission as usual: he explains that the area surrounding the Capitol has been filled with “pods”—essentially, futuristic land mines—that release dangerous objects when they’re activated. Before defecting to the rebel cause, Plutarch stole the holographic plans for the pods, meaning that the mission members will be able to tell which pods are dangerous and which are decoys.
Katniss and her mission arrive in the Capitol. They spend the next several days shooting at pods. Katniss is bored, and secretly plans to run off on her own to find Snow and kill him. Just as she’s finalizing her plans to do so, a new member of the mission arrives: Peeta, who’s slowly been recovering from his conditioning. Katniss is horrified that Coin has sent Peeta to be with her, and privately wonders if Coin wants her dead. She discusses this with Boggs, who grimly tells her that this is entirely possible—Coin wants to eliminate potential rivals as soon as possible. Boggs orders that Peeta be watched around the clock so that he doesn’t have any opportunities to attack Katniss.
One day, Boggs walks through an abandoned building outside the Capitol, and accidentally activates a bomb that blows off his legs and kills him. Before he dies, Boggs passes his holographic plans of the pods to Katniss, and warns her, “Don’t trust them.” The ensuing chaos reactivates Peeta’s Capitol conditioning, and in the struggle he kills a rebel soldier by pushing him into a nearby pod. The remaining rebel soldiers restrain Peeta by knocking him out and handcuffing him.
In the aftermath of the explosion, Katniss lies and tells Jackson and the other soldiers that she’s on a secret mission to kill Snow. To Katniss’s surprise, the camera crew goes along with this lie and pretends to have been given the same instructions. Jackson reluctantly agrees to go into the Capitol and find Snow. When Katniss asks the group what they should do next, Peeta whispers that they should kill him. He explains that he’s become a danger to the mission—he could kill Katniss at any time. Katniss refuses to believe this, and insists that she’ll keep Peeta alive.
The mission enters the huge network of tunnels underneath the Capitol. There, Katniss is horrified to find a Pod called the Meat Grinder, which kills Finnick and alerts an army of “mutts” (half-human, half-animal soldiers of the government) to their presence. The mutts chase the rebels through the tunnels, with Jackson bravely staying back to defend her fellow soldiers. Once Katniss and the others have run away, they activate an emergency bomb contained in the holograph, blowing up the army of mutts. Katniss is amazed that Peeta has stayed calmer than any of the other soldiers. She tells Peeta that she’s afraid, and kisses him. He kisses her back, and tells her that he won’t let Snow kill her.
The remaining members of the mission proceed to the house of a woman named Tigris, who is sympathetic to the rebel cause. Tigris gives Katniss and her friends elaborate disguises and warm clothes, and points them in the direction of Snow’s mansion. The night before the mission is scheduled to leave, Katniss overhears Peeta and Gale talking about her. Gale says that Katniss always chooses whichever one of them “she can’t survive without,” a suggestion that hurts her feelings, but which she can’t entirely disagree with.
The next day the mission sets out for Snow’s mansion. Before they can get far, there is a riot, followed by an air raid. Government soldiers, recognizing Katniss and her friends, shoot at them, and in the chaos Katniss is separated from the mission. Stumbling through the crowds of rioting citizens, Katniss sees parachutes falling from the sky. The parachutes contain bombs, which blow up a huge chunk of the city. After the explosion, Katniss sees a girl running toward the area of greatest damage, trying to help the injured. To her horror, she realizes that this girl is Primrose, her own sister. There is a second round of explosions, even deadlier than the first. In this second explosion, Primrose is killed, and Katniss loses consciousness. In her unconscious state, she sees the faces of the dead, including her own father.
When Katniss awakes, she finds that the rebels have won the war, and President Snow has been defeated. Katniss goes to visit Snow in jail, remembering that she is to kill him. In prison, Snow tells Katniss that, contrary to what she thinks, he’s not responsible for Primrose’s death. On the contrary, he says, President Coin bombed citizens of the Capitol in a clever attempt to turn Snow’s own people against him. Snow adds that Katniss has been a decoy: by sending Katniss all over Panem, Coin distracted Snow and made him waste his resources trying to kill her. This has made it easy for Coin to win the war. Katniss remembers the double bomb that Gale and Beetee showed her, and realizes that Snow is probably telling the truth.
Soon afterward, Katniss is informed that she is to execute Snow before a huge audience of people. Before the execution ceremony, Coin—now the president of all of Panem—holds a meeting of the remaining Hunger Games competitors. Coin proposes that the Hunger Games be banned forever, but that first, one final Hunger Games be held for the citizens of the Capitol, who have previously been exempted from the vicious tradition. Peeta votes against the idea, but the other competitors, including Katniss and Haymitch, support it.
As the execution ceremony begins, Katniss realizes that Snow has been telling her the truth about President Coin: Coin was responsible for Prim’s death. Katniss steps up to perform her role of executing Snow, but instead aims higher and shoots Coin with her arrow. Katniss is imprisoned for her crime, but Haymitch and Plutarch are able to “get her off” by arguing that she’s been traumatized by her experiences in war. When she is freed, Plutarch explains that Commander Paylor is the new president of Panem, and that he and Gale have been given powerful roles in the new regime.
Katniss ends up with Peeta. Peeta sympathizes with Katniss’s pain and trauma, and is, she now realizes, very patient and gentle, in stark contrast to Gale. In the novel’s epilogue, set twenty years later, it’s revealed that the Hunger Games have been banned, and Katniss and Peeta have become legendary heroes, thanks largely to Plutarch’s influence. Together, they have two children. Katniss still has nightmares about war and violence, but she’s happy to be with Peeta.