The super-secret mission to the center of the moon (pie)

A band of young geniuses blast off for the Moon on a mission that rapidly morphs into an attempt to prevent the alien YAKs from destroying an entire plane of reality. De la Cruz continues to braid together two storylines of equal heft in this middle volume. In one strand, her young Octos, brought together at the Octagon Valley Institute by the eccentric Onasander Octagon, struggle with conflicting loyalties and resentments; some explore not-entirely-welcome new superpowers, while others jealously await their own powers (if any) to manifest. In another, they battle the malign YAKs over the fate of the multiverse. With her authorial tongue firmly in cheek, de la Cruz often writes chapter headers like "Game of Thorns," and the book's title is entirely accurate, thanks to a gooey mishap with a high-tech Object-Shifter. Amid all the squabbling, fretting, and hesitant bonding, the young heroes arrive on our nearest astronomical neighbor just in time to infiltrate a YAK summer camp and compete in the Cosmic Games, which are designed around their individual personality traits. By the end, the destruction of the universe is at least delayed, and if the omniscient narrator leaves a few mysteries unanswered (such as what YAK stands for: "Young Angry Kittens? Yellow Amoeba Karts?"), a closing teaser offers a chance of resolution. A masterful opening recap includes references to the cast's previously established racial and cultural diversity. Nonstop lunar lunacy.(Adventure. 9-12) Copyright (c) Kirkus Reviews, used with permission.