Where We Left Arya
In the disguise of Walder Frey, she murdered each Frey man by posioning their wine. She went to Winterfell where she had a clash with Sansa whom she feels is not faithful to Jon. She finds a letterthat Lannisters made Sansa write. That was a trap set by Baelish. It was thought that the letter would separate the sisters. But they finally come together and find that Baelish was their enemy.
