After training with the Faceless Men in Braavos, Arya Stark heads to Westeros to kill more enemies on her revenge list. She makes her way to the Twins, seat of House Frey, and the same location where her mother, brother, sister-in-law, and most of the Stark armies were massacred in the Red Wedding - an unthinkable violation of guest right, which Lord Walder was outright proud of. Arya infiltrates the castle by disguising herself as a servant girl, using one of the magic shapeshifter masks she acquired from the Faceless Men to alter her appearance.