Surrender to the will of the night2010
by Glen Cook
The old evils, the Instrumentalities from the Time Before Time, have begun to ooze back into the world and Piper Hecht's sister Heris and his living ancestor Cloven Februaren, the Ninth Unknown, have made Piper part of their fight against the return of the dark god Kharoulke the Windwalker.
— from OpenLibrary
3 editions at OpenLibrary