It is a credit to Yolen as a writer that she can create a magical realm and convince the reader that it is real. The house she describes is like the one that she and her family occupy in Scotland during the summer. This house is in two worlds: one in which it is a comfortable home with plenty of books and a well-stocked pantry, and an alternate world in which the house is full of noisy motion. Yolen has taken a stock idea from science fiction for this part of her story. The houses are also part of the gothic tradition. The Wild Hunt, Herne the Hunter, with his antlered helmet, and the Moss Man are stock figures in medieval folklore, although in some parts of England people still believe that the Wild Hunt occasionally rides. Suspense is necessary for a ghost story, and Yolen...