I am not sure how this plays out in the books as I haven't read them, but I just watched the last episode of Game of Thrones and it went down like this:
- Arya gave her dagger to Sansa at the beginning of the episode before Sansa made her way to the crypt.
- A whole lot of events went down.
- Arya finds out she is supposedly meant to kill the Night King and goes full commando.
- At some point after this moment we see the dagger still with Sansa, which is also verified by the fact that Tyrion saw it and was like "Yeah, cool, Valyrian Steel dagger! Let's rock it!".
- Arya goes Assassin's Creed on the Night King's dead butt with the dagger.
Is there something I'm missing here or did the dagger just teleport between the two?