I think

Arya will kill the Waif after a long and bloody battle.

EITHER Jaqen will say one way or another, a face was added, you can't come back, go now forever (but we're not coming after you)

OR she just runs away and the threat will hang over her for the rest of her life, that the Faceless Men will hunt her down and kill her, which they're probably quite likely to succeed in doing as they're rather good at that kind of thing.

I'm hoping for the former, natch, but this is Game of Thrones...

Posted By: Old Man, May 30, 18:56:39