[font=Century Gothic]Maybe the whole zombie movie scene where Arya eludes the walkers was the prelude to her sneaking up on the NK.
1. Arya being a badass killing undead while The Hound is paralyzed with fear;
2. Arya being all stealthy in the library, where only the sound of her dripping blood gives her away;
3. Melisandre reminding us of her prophecy, but switching the order of the eye colors so that "blue eyes" comes last;
2. Arya refocusing and recharging after hearing Melisandre, and then zooming off to who knows where.
It was there. We just didn't piece it together properly... because the producers and director purposely gave us long shots of Jon yelling "Bran!" to Dany before trying to fight his way to the godswood to protect/save Bran. They give us SO much Jon that we're certain he's going to be the one to kill the Night King. It's just enough time for us to have let Arya slip from our thoughts.
I've rewatched this a few times (on the second computer monitor while I'm working), and I'm finding that I really *like* the way they did this.
Now I want a scene in episode 4 where she gets the respect due to her for this amazing feat.
And maybe some reward money to fix those googly eyes or something. Right, @Sedai ?