All's Fair - Katherine Perkins - Bog

Late December is a magical time of year. Magical enough for the forces of the Fomoire to truly begin their conquest. Many people travel and consider new things during a gap year before college. Megan of the Unseelie, all of 18 now, is spending hers hurrying between realms and trying to figure how to stop the Fomoire from running rampant over all worlds when the Winter Solstice arrives. Now Megan must rally her friends and allies one more time in a last, desperate mission. Especially because some on both sides say all those worlds are doomed.