Hoping to enhance her magical powers, a clever squirrel embarks on a journey of self-discovery. Holly lives at the Shelter for Rejected Familiars with other disappointed animals. All shelterlings once hoped to become wizards' familiars, but when their magical powers were deemed too insignificant to be of use, they were sent instead to the shelter, a pleasant enough place but one none of them wanted to end up in. Holly's supposedly useless magic is an ability to conjure pastries; her barn owl pal, Gus, can transform himself into a granite statue; and a lemur named Periwinkle finds lost things. When beaver Charlie, a former shelter resident, suddenly returns seeking help in locating seven magical ingredients critical to recasting a spell to cure the shelterlings' defective magic, Holly volunteers. Despite her misgivings, she longs for adventure and surprises herself by negotiating with a greedy dragon to retrieve a magical flower, convincing a hungry orca to recover a magical pearl, and coaching Periwinkle to find a piece of fallen star. When Holly discovers Charlie intends to betray the shelterlings by transferring their magical powers to himself, she must stop him. In an action-packed finale, Holly and the shelterlings rely on one another and discover their unusual magic may not be useless after all. The bevy of animal characters with their peculiar personalities and special powers provide humor and variety. An amusing, fast-paced fantasy with an impressive rodent hero. (Animal fantasy. 9-12) Copyright (c) Kirkus Reviews, used with permission.