Did they already have a "truce" or whatever with the NK from long ago? First, they did not portray him as someone who could even do that, second, if he could do it once, seems like it would make a bit more sense than killing him the way they did.
The show hasn't shown any other side to the Night King besides being a zombie essentially, so I doubt it, there is some hope in the books to there being more. This Truce you speak of is a big fan theory, but it may just be nothing in the end like the show.
Huh. I could have sworn the show mentioned it, but I might be wrong.
Also if he's just a zombie, then how did he make whatever deal with Craster? I doubt that dude just randomly started leaving babies out and the Wights just were like "well....guess we keep him alive?" Feels like some level of organization and communication had to go into that set up.
This is a question that comes as much from my interpretation of the books as well as from the show, there is no concrete evidence for Craster's communication with the Others or lack thereof so people might have different opinions.
But, for myself I absolutely do not believe that Craster and the Others had a literal "deal" in the same way two sets of people have a deal. I think that there was some sort of "understanding" between the two sides but it was very asymmetrical. As far as Craster was concerned, he was sacrificing his sons to "the gods" (as he himself called them) and he and his home were protected, somehow. As far as the Others were concerned, they had a source of newly born children that they can transform into White Walkers - whether they can do it with any children or there's something special about Craster or the nature of their "arrangement", we don't know. But I would be absolutely shocked if there was ever some moment where an Other came and spoke to Craster and they drew up some sort of contract or sealed a pact in words. I don't believe Craster really knows what's happening or understands the significance of it. I actually think he did stumble upon the arrangement, perhaps from his own ancestors whoever they were. Or if he was influenced to do it, it would be through something indirect like dreams or a vision, rather than an Other coming and pitching him the idea. I think that's exactly in line with the way that Martin treats magic and mysticism in his books; magic in the world of Ice and Fire isn't usually a sort of "Functional Magic", where you can know the components or the words to cast a spell and achieve something very specific. Certainly not when it comes to the big things. That's one of the reasons there are so many mysterious things at work in the series - it's also the reason I think a lot of fan's attempts to "explain" them in a more rigorous, pseudo-scientific way are misguided. It's like trying to work out whether in order for Daenerys to hatch the dragons it absolutely
had to be the pyre a dead Khal you were married to and a maegi learned in blood magic screaming as she burned around the time a red comet appeared in the sky. I think in the world of GRRM, all of that mattered, but not because it's some formula that can be applied. The nature of magic is more along the line of miracles - it's unique to the circumstances and not something that can be easily explained.
But, like I said the books or show don't go into any detail either way on Craster's "arrangement" (in the books it's not even confirmed the Others are taking the babies and turning them), so other fan's can have their own opinions.
One more thing. So I know the show has never said anything about this, and it's all just speculation on my part. But I always had the impression that the NK had some kind of foresight. When Dany came with the dragons, he seemed VERY prepared for such a random and unpredictable (to him) event. Dude had spears ready to go and even had the chains necessary to drag the dragon out of the water. So I'm left to believe that either A) He just carries those chains with him that serve virtually no other purpose, or B) Was able to see all of this happen and was prepared well ahead of time. If it's B, then his death makes even less sense to me.
I think the Night King definitely has some sort of foresight, or greenseer like ability. The fact he is able to interact with Bran in a vision, and detect Bran watching him through ravens, suggests this. As do the events of Beyond the Wall. Personally, I think the chains aren't really that big a focus - one thing that has been consistent from beginning to end, even through the Long Night, is that the White Walkers are a much more organised and competent force than most give them credit for (not spotting Arya rushing the Night King aside). Getting ahold of big chains shouldn't be considered that big a deal for them, and even though Viserion was hauled out of the lake at the end of the episode that doesn't mean it happened straight after, it could have been hours or days or [insert however long needed to go fetch chains] later. But since I think they did predict the coming of the dragon they could have made arrangements to have the chains closeby. I think the fact they predicted it is shown more by the way they trapped them on the frozen lake and waited, and the way the Night King reacted to the arrival of the dragons.
However, even for the likes of Bran, Melisandre and others, seeing the future isn't always clear. Bran can see view the past and things that are going on in the present with some control, but from what we've seen he only gets some visions of the future and hasn't been shown to be able to control or choose what he sees. If the Night King is similar, then just because he has some measure of "sight" doesn't mean he should know everything that's going to happen.
My interpretation though was that when the Night King came to kill Bran and Bran was just waiting for him doing nothing, they were essentially having a "vision-off" - Bran knew or sensed that the Night King would die there and the Night King didn't know or couldn't see it. That's why he had that curious look when he got to Bran. So basically if the Night King did have some sort of foresight, Bran's foresight "beat" his (because Arya was somehow able to get past all the White Walkers, which many people find questionable, but I think that's the general idea).