Now in seventh grade Belle Song has settled into her life on Mars; she has a new baby sister, her android Melody, her wolfdog Raider, and her friends, the human Lucas, and the Nabian, Taal--but when she and Taal uncover some ancient ruins which the Nabians claim are a sacred site, Belle finds herself plunged into a tricky world of extraterrestrial politics and religion that threatens her relationship with Taal.