Game Of Thrones Season 7 - Episode 7 -

Littlefinger thought he had successfully turned the sisters against each other.

The Night King arrived at Eastwatch-by-the-Sea riding the resurrected Viserion. Game of Thrones Season 7 - Episode 7

The season-long tension between Sansa and Arya Stark reached a boiling point, only to take a sharp turn. Littlefinger thought he had successfully turned the sisters