It has been six months since Katniss Everdeen and Peeta Mellark won the Seventy-fourth Hunger Games, an annual event in which each district in Panem sends one female and one male tribute to fight to the death in a televised competition for food and money. Though only one tribute can win, a change in the rules allowed Peeta and Katniss to both win. Their victory was partly secured because of Peeta's declaration of love for Katniss before the Games.
In the Hunger Games, after Peeta and Katniss were the only ones alive, it was announced that the change in rules had been revoked, and there could only be one victor. Instead of killing Peeta, Katniss proposed they eat poisonous berries to kill themselves so that the Capitol would not have any victors. But at the last second, they were both declared winners of the Hunger Games. Throughout the competition, Katniss played along with the love story so she could increase her chances of winning, though secretly she was confused about her true feelings for Peeta and Gale, her best friend who was back home in District 12.
Peeta, whose love for Katniss was never an act, was broken-hearted at the realization that Katniss was merely pretending to love him for the sake of the competition. Since the Games, he has been acting very distant and cold toward her, and she feels guilty for the way she treated him. Gale has also been treating her differently since she returned home. Nothing is the same for Katniss since winning the Games.
When the novel opens, Katniss is hunting in the woods, thinking about how much she doesn't want to go on the annual Victory Tour. Every victor of the Games must visit each district to celebrate their win at the Games. After hunting, she returns home so she can ensure she is ready in time for the Tour, only to find that President Snow, the leader of Panem, is waiting to speak with her.
Snow tells Katniss that she needs to convince both him and Panem while on the Tour that she is in love with Peeta or the Capitol will go after her and Gale's families. According to Snow, Katniss' stunt with the berries was too rebellious. Though some people believe she was proposing suicide because she was so insane with love for Peeta, others think it was an act of defiance. Some of Panem's districts are now on the brink of rebellion. If Katniss can convince everyone she is without a doubt in love with Peeta, Snow will spare her family's lives.