In "Mockingjay," the final book of the futuristic "Hunger Games" trilogy, author Suzanne Collins can no longer rely on the plot device that made her previous books so powerful and entertaining: the battle arena. Imagine Harry Potter without Hogwarts, or "The Matrix" without the Matrix. The best parts of the previous novels in the series, "The Hunger Games" and "Catching Fire," take place in a vast, booby-trapped arena where 16-year-old Katniss Everdeen fights other kids to the death in a cruel, government-enforced competition.

The Capitol televises the bloody contest each year to entertain the ruling class and to remind the workers where they stand. In both novels, the preparation, battle and aftermath of the Hunger Games are riveting and fascinating. In comparison, "Mockingjay" flounders at first. So does Katniss: "What am I going to do?" she wonders on several occasions. "Is there any point in doing anything at all?"

But Katniss discovers that she has much to do. She is the symbol of the revolution, whether she likes it or not, for her performance in the Hunger Games and her defiance of evil President Snow. Her people, the working class, are openly at war with the Capitol, and she must determine her role. She also must sort out her feelings for two boys, Gale and Peeta, both of whom change as a result of time and circumstances.

Katniss travels to the mysterious District 13 -- headquarters of the resistance -- because the Capitol has bombed her home district to ash. In previous books, Collins builds up curiosity about District 13, and now she unveils the underground city in all its complexity. The result is satisfying. District 13 is no safe haven -- no Hogwarts where Katniss can frolic with other kids under the watchful eye of a kindly headmaster. While the Capitol resembles the passive and superficial contentment in Aldous Huxley's "Brave New World," District 13 begins to resemble the domineering government in George Orwell's "1984." Katniss is caught between them, so her floundering is understandable. She tries to ignore the daily schedule that a machine imprints on her wrist each morning. For instance, she is required to engage in "Reflection," which sounds sinister -- perhaps a precursor to Orwell's Thought Police or Two Minutes Hate. District 13 is not what she had expected.

As Katniss reinvents herself and finds her identity, so does the story. Like fellow author of teen fiction J.K. Rowling, Collins is a master of plot twists and reversals. Many chapters end with a surprise, often a violent one. While "Mockingjay" is "futuristic" rather than fantasy, Collins rivals Rowling with her inventiveness and storytelling.

Doug Pond is a Minneapolis-based writer.