“This war has just begun. It will last for years.” The words emerged from Melisandre like so much secondhand smoke, but they could well be coming from the HBO executive boardroom. As year two of this grand, multivolume experiment in adaptation and decapitation comes to a rousing close, it’s clear that the network would be perfectly happy if peace never came to Westeros at all. Most season finales of cable dramas are, like Jon Snow, stuck playing a double game: attempting closure on the one hand and, on the other, teasing future conflicts. Game of Thrones, by contrast, goes completely Halfhand; after 20 hours of this sprawling story, only one thing is eminently clear: We’re just getting warmed up.