Given the ending for Book 12: Nightshade, I feel it is more than likely that there's going to be a Book 13. The question is, when is it going to come out? Has Horowitz already started working on it? What is it going to be about? We know Nightshade is going to come after Alex, the real question is, is Alex finally going to get a real break before this happens. At least he's shown he's more of a willing participant for next time, o at least he's doing it less against his will now.