Is "dammit, Seanan!" a complete review?
This is one of the few prequels that you have to read after the original because the ways in which it is heartbreaking depends on Every Heart a Doorway and the ways/places of being established in that book. But it's shiningly brutal in its own right and I love Seanan when she's writing in fairy tale mode. I may need to go back and reread "How the Maine Coone" now to make myself feel better.