The following contains spoilers for Game of Thrones season seven.

There's nothing like rifling through your sister's bag and finding a bunch of faces, which is precisely what happens when Sansa discovers Arya's creepy collection during the latest episode of Game of Thrones [1]. Pulling out what looks like a rubber mask from a Halloween [2] shop, Sansa is understandably freaked out, and Arya does nothing to reassure her. Instead, Arya vaguely acknowledges the Faceless Men [3], explaining that the faces allow her to choose who she wants to be. "I can become someone else, speak in their voice, live in their skin. I could even become you," she says, grabbing her dagger. But right as it looks like she might actually kill her sister [4], Arya flips the dagger around and hands it to Sansa. See how people reacted to that wild Game of Thrones scene, then check out the theory about Arya and Littlefinger [5] that makes the sisters' dynamic all the more intriguing.