User blog comment:SophitzFoster/Things I Learned at the Book Signing!!/@comment-72.73.39.15-20181118211304/@comment-32247874-20181119205716

Well, because we keep making Keeper a best seller, her publishers decided to let her know they would publish book 10 if needed. Originally she got a three-book deal, and then then let her add Neverseen, then Lodestar; after Lodestar, they said they would sign for books 6 and 7, and then after Nightfall's huge success, they said "Okay, how about 8, 9, AND 10?" So if the book is needed, there will be one.