I love McKillip (and yeah, her cover art has rocked for a while).

It's an Ace book, and is -entirely- in open distribution -- I noticed it had come out in hardback when I searched scifan for interesting new books, so we snatched it up at Collosium books.

Sere is the one with the Baba Yaga analogue; if you've read the book, you -will- remember that much. :)