Catching Fire is the middle novel in The Hunger Games Trilogy, by Suzanne Collins, and details the aftermath of the 74th Annual Hunger Games in the dystopian world of the future.
The main conflict in the book comes from the interaction between Katniss, the young co-winner from the first book, and President Snow, who wants to use her as a tool of quelling rebellion in the Districts. Katniss wants to be left alone to return to her normal, pre-Games life, but as the novel progresses she begins to see the true brutality of the Capitol and its methods, becoming sympathetic to rebellion. Near the start of the book, Snow and Katniss have this conversation:
"...people viewed your little trick with the berries as an act of defiance, not an act of love. And if a girl from District Twelve of all places can defy the Capitol and walk away unharmed, what is to stop them from doing the same?" he says. "What is to prevent, say, an uprising?"
It takes a moment for his last sentence to sink in. Then the full wight of it hits me. "There have been uprisings?" I ask, both chilled and somewhat elated by the possibility.
"Not yet. But they'll follow if the course of things doesn't change. And uprisings have been known to lead to revolution."
(Collins, Catching Fire, Google Books)
This shows that Snow understands the effect Katniss has, unintentionally, on the rebellious people in the Districts. For her part, Katniss slowly realizes that she has become a symbol for freedom against the Capitol, and although she tries to keep in line with Snow's demands, she intentionally and unintentionally sets the stage for the final uprisings in the third book.