F. C. Yee's The Shadow of Kyoshi is strikingly different from its predecessor. Whereas The Rise of Kyoshi's "water arc" focused on Kyoshi's origins and the happier moments in her relationship with Rangi and Yun, and its "earth arc" reveled in lush Earth Kingdom world-building and Kyoshi's travels with the Flying Opera Company, The Shadow of Kyoshi (the "fire arc") is a much more grim tale. As Kyoshi has begun settling into her Avatarhood, the kinds of problems she has to deal with also become more complex (and more political), and their solutions aren't always clean and pretty. To showcase these complex problems, The Shadow of Kyoshi smartly takes place in the Fire Nation, a natural setting for tense political infighting.The first half of Shadow features a rare, rich dive into the lore of the Fire Nation, into its history, its culture, its rigidly Confucian social norms, and into its ever-present internal power struggles. I find Yee's writing for the Avatar series is at its best when he focuses on world-building, and the way he paints the lore of the Fire Nation is truly immersive and mesmerizing as the culture of the volcanic islands unfolds and comes to life before our eyes. The latter half of the book is more focused on the plot at hand and on Kyoshi's own development, but it builds up to a showstopping moment in the final act that is truly satisfying both for fans of the novel series and fans of the Avatar universe as a whole.I really hope there are more novels to come. Kyoshi lived 230 years, so I'm pretty sure there's plenty of room beyond her first 17 years of age for more of Yee's wonderful prose and Kyoshi's difficult and raw journey through her Avatarhood. This novel series might be the best Avatar series since the original ATLA, and, as such, is a must-read for Avatar fans.