Thompson closes the trilogy begun with Switchers (1998) by bringing young shapeshifter Tess to her pivotal 15th birthday, after which her ability to change into any animal will be lost. Or maybe not, as she discovers. An unhappy visitor to relatives in rural County Clare, Tess agonizes over which shape to take as her permanent one. The plot thickens when three cousins vanish into the same eerie patch of woods that swallowed an uncle 20 years before. In tracking them down, Tess learns not only that a pale remnant of the fairy folk still exists in their underground “fairy sidhes” but also that their blood runs in her veins. Suddenly, her decision becomes even tougher, for with just a bite of fairy food her powers will remain and expand—at the cost of losing her connection with time, humanity, and the natural world. Plainly a devil’s bargain. The story develops slowly compared to the first two installments, and stands alone only by virtue of repeated back filling, but readers will see how tempting each of Tess’s options are, and how her previous experiences influence her eventual choice. Tess’s forays into animal worlds and realms of magic thread this coming-of-age tale with humor and melodrama. (Fiction. 11-13)