"Hardhome" was edge-of-your seat exciting. And, truthfully, quite terrifying. It's been a long time since the White Walkers felt like a threat, and sometimes we go too long hearing people just talk about them. But then - boom! - the show will do something like this that instantly reminds you why they're public enemy numero uno. And why one of the major houses of the realm, essentially, made their motto all about them.