Sometime after Katniss Everdeen and Peeta Mellark return to District 12 following their victory in the 74th Hunger Games, President Snow visits Katniss and explains that her actions in the Games have inspired uprisings. He orders her to use the upcoming Victory Tour to convince people that her actions were out of love and not defiance against the Capitol, warning her that her friends, family, and District 12 will otherwise suffer, but she is unsuccessful in doing so. During the tour, Katniss’ mentor Haymitch Abernathy warns her that she and Peeta, as Victors like him, will now have to serve as mentors to future tributes and that their show of love will be forced to continue for the rest of their lives.
Peacekeepers enter District 12 to crack down on illegal activity, and Katniss’s friend Gale is publicly whipped after attacking the Head Peacekeeper. However, Haymitch, Peeta and Katniss use their influence as Hunger Games victors to save Gale from being executed. This is broadcast on state television; in response, Snow decides that the Hunger Games victors have too much power and need to be eradicated. He announces that the upcoming Hunger Games – the 75th overall and the third Quarter Quell – will involve tributes selected from previous victors, allowing him to dispose of almost all of them. Katniss is devastated, knowing she will be forced to participate as she is the only living female Victor from District 12, and she immediately devotes herself to ensuring Peeta survives. On Reaping Day, Haymitch’s name is drawn, but Peeta immediately volunteers to take his place. Haymitch reveals that the tributes are angry about being forced to return to the Games and will most likely attempt to stop it. For her pre-Games interview, Katniss wears a wedding dress, as ordered by Snow, but her stylist Cinna sets it to transform into a symbol of a mockingjay. Peeta announces that he and Katniss, who had previously announced their engagement during their Victory Tour in an unsuccessful attempt to quell the Districts, are expecting a child. The citizens then protest for the Games to be stopped to no avail. Just before Katniss enters the arena, Cinna is severely beaten by Peacekeepers in front of her as punishment for his tampering with her dress and then dragged away.
In the Games, Katniss allies with District 4 tributes Finnick Odair and the elderly Mags, his mentor. When the arena’s forcefield shocks Peeta, stopping his heart, Finnick revives him. The group is then forced to flee from a poisonous fog; when Peeta cannot go on, Mags sacrifices herself so that Finnick can help him. When mandrills attack, Peeta is saved by the unexpected sacrifice of a hiding tribute. The group escapes to the beach, where Finnick greets District 3’s Wiress and Beetee and District 7’s Johanna Mason. Wiress repeats the phrase “tick-tock”, leading Katniss to realize that the arena is designed like a clock, with unchanging hazards each hour contained within their respective zones. Wiress’s throat is slit by Gloss, one of the Careers. Gloss is then fatally shot by Katniss while Johanna kills his sister, Cashmere. Finnick is injured by another Career, and the Gamemakers spin the clock to disorient the tributes.
Beetee suggests luring the rest of the Careers to the wet beach and electrocuting them, which was how he himself previously won the Games. The group separates to prepare the trap. When Brutus and Enobaria emerge, Johanna cuts the tracker out of Katniss’ arm and flees. Katniss finds an unconscious Beetee. Unable to recover Peeta, and hearing a cannon (Peeta killing Brutus), Katniss almost kills Finnick, thinking he betrayed them, but he reminds her to remember who the real enemy is. Katniss attaches some wire to an arrow and shoots it into the arena’s roof just as lightning strikes a nearby tree to which the wire is attached. The roof of the arena breaks and the lightning strike paralyzes Katniss and incapacitates Finnick. It also causes a power failure that brings down the dome and disables the security cameras, preventing the Capitol from observing the events.
Katniss awakens in a hovercraft with an unconscious Beetee. She finds Haymitch, Finnick, and Plutarch Heavensbee, the new head Gamemaker, who reveals himself to be a rebel against Snow. Katniss learns they are bound for District 13, the headquarters of the rebellion, and that half the tributes were recruited to help Katniss escape, as she is the symbol of the growing rebellion. After further learning that Peeta and Johanna could not be rescued and are now captives in the Capitol, Katniss furiously attacks Haymitch for not keeping his promise to protect Peeta, but is quickly sedated. She awakens to find Gale by her side. He assures her that her family is safe, but also reveals that District 12 has been destroyed after Snow was made aware of the rebels’ plot.