My favorite of all her books. I generally dislike the writing style, characterization, and plot of Seanan McGuire novels, but I adore her writing as Mira Grant and find myself trying all the McGuire writing just in case. 
 This book was perfect for me, the world building was FANTASTIC. I love the idea of doors, and the schools of children. It's like someone personally wrote the perfect book for me. Magical.