In one of her periodic posts on fantasy and science fiction novels at Tor.com, award-winning novelist Jo Walton says there are two ways to plot out a fantasy series after the big bad has been destroyed. The first way is easier but also less satisfying and involves simply saying that the evil wizard (or whoever) had a second in command or left a way to resurrect himself, that he needs to be defeated again. (For a non-fantasy context, think of how “Return of the Jedi” brings back the Death Star the Rebel forces destroyed in “Star Wars.”) The harder but much more satisfying version of a continuation involves revealing all of the evil forces the big bad was keeping in check, descending into the chaos that comes when an orderly system is replaced by disorder. It is about crumbling ruin and what was once at least stable turning to dust. An evil regime has been removed, but at what cost?