Oh my god...
Best episode yet? Seriously. From beginning to end, impactful moment after impactful moment. The whole episode left me with such a terrible feeling, though. I don't trust Locke at all. Jon is being sent into an incredibly perilous situation, and I can't help but feel it's not going to end well. Then there's Team Bran being captured, slapped around, and stabbed (poor Hodor...). It's so strange seeing Bran in that situation. And then it's all capped with a closer glimpse at this ridiculously ominous force stirring in the background.
A random observation: something core to Dany's character arc is that it's almost completely disconnected from events in Westeros. That's something she actually shares with the White Walkers, but in her case, the show intimately focuses on her story. Something the show does often is have something bad happen in Westeros, but then give the viewer hope through Dany's story - there's a pretty constant contrast there.
In general, there's several forces that exist in the background of the more immediate events of Westeros, and that's something that makes the story so much more interesting. You have Dany representing a more hopeful force, the White Walkers representing a darker one, and even the weather itself is something that's eventually going to change the entire game.
My observation is this, though: whereas usually Dany's story is used to uplift the viewer, in this case, her scene came at the very beginning of the episode. And soon after that, came tension filled scene after tension filled scene, ending with a glimpse at the force in the background that will almost certainly cause an incredible despair down the line. This episode was the opposite of hopeful, and it seemed almost intentional.