Readers longing for a return to Camp Half-Blood will get their wish in the first novel of the Heroes of Olympus series, which follows Riordan’s popular Percy Jackson and the Olympians series and includes some of the same characters in minor roles. The new cast features Jason, Piper, and Leo, teen demigods who are just coming to understand and use their unique abilities as they learn how much depends upon their wits, courage, and fast-developing friendship. Setting up the books to come, the backstory of a master plan to unseat the gods is complex but is doled out in manageable bits with a general air of foreboding. Meanwhile, the action scenes come frequently as the three heroic teens fight monstrous enemies in North American locales, including the Grand Canyon, Quebec City, Detroit, Chicago, Omaha, Pikes Peak, and Sonoma Valley. Flashes of humor lighten the mood at times, but a tone of urgency and imminent danger seems as integral to this series as the last. With appealing new characters within a familiar framework, this spin-off will satisfy the demand for more. Grades 4-8. --Carolyn Phelan