Chute concludes her fantasy trilogy with a tale of humans and other beings united to save a multitude of worlds.Archie Wellsley's attempt to save his teen granddaughter, Ella, ultimately led his family to the parallel world of Jarr and its magical island, Jarr-Wya. Though Ella is still dying from cancer, which also robbed her of speech, she's befriended nonhumans like the Steffanus, a winged, silver-skinned "she-race." Unfortunately, the magic in Jarr, called Naiu, is slowly withdrawing, and its absence would mean the end of all worlds. Finnah, a living Star beneath Jarr-Wya, can stop Naiu's retreat, but she, for whatever reason, wants a key that Ella owns-and she wants Ella to deliver it. While the various races, including rocklike Bangols and fire-inducing Olearons, debate who will journey to Finnah, Ella leaves with her Bangol love, Luggie. Everyone else must battle Senior Karish, who leads the Millia, vicious beings made of crushed seashells, who crave Finnah. As another enemy's approach only compounds their predicament, Ella telepathically communicates with her mother, Tessa, to find a way to defeat the villains. Chute's finale is practically overflowing with vibrant characters, and she imbues each of them with distinctive personalities (morally ambiguous Zeno and hard-boiled but compassionate Callisto). The story hums along, but characters' quieter moments are the standouts. A highlight is tenderness between Ella and Luggie, during which she must remain cautious of his piercing nails and bladelike teeth. While the story notes Ella's imminent sacrifice, the selflessness of numerous individuals, like those who sadly fight to the death, is impossible to miss. It makes for an uplifting tale, augmented by Chute's memorable artwork.A worthy end to an inspired, remarkable series. (maps, glossary, character family tree, acknowledgements, author's note, author bio)