Fall, the second book in my Witch Season teen horror quartet (and the one that was nominated for a Stoker Award, back when they had a young adult category) is out of print, even though the other three are still available.
But sometime this summer, they'll be easier to find.
Barnes & Noble (and their Canadian counterpart Indigo) are publishing a special, proprietary re-bind of the first two books, Summer and Fall, combining them into a trade paperback edition. This will be oversized and shelved with all the big fantasy books, Harry Potters and so on. If it does as well as they think, they'll also do the second two books.
I'll let you know when they're available.