The biggest mystery of this series is the true character of Snape, the most fascinating character of the series. Rowling claims to find fans' fascination with Snape inexplicable, that she finds him straightforwardly horrible. But she keeps building in reasons to believe he may in fact be on the side of good. In this volume Rowling finally has Snape cross the line... or does she? There is still room for doubt, especially if you want to believe in Snape's redemption. We shall see.