*Warning: Spoilers ahead*
Obvious spoiler: We all know the moment that we realized Littlefinger's last day was finally here. In Winterfell's Great Hall, Sansa looks over at Lord Baelish after listing off the accusations for murder and treason (seemingly against Arya). But did Sansa know all along, or was she really tricked by Littlefinger?
Game of Thrones fans have debated this question at length, but we finally have an answer for when exactly Sansa finally awoke from Petyr Baelish's spell. Per Vanity Fair, who recently combed through the Game of Thrones scripts that are on display at the Writers Guild of America West library, the season seven writing makes it clear that she was only aware right at the end. All those steely fights between her and Arya were real.
When Arya continues to accuse Sansa of helping Joffrey when she was married to him, Sansa is genuinely upset. It's not just some scheme to trick the viewer into worrying what will happen if the sisterly tension keeps escalating. The script reads: “Now she grows angry, and when Sansa gets angry a steeliness enters her tone.”
It's not until the season seven finale that Sansa truly realizes Littlefinger's betrayal, when Lord Baelish tells Sansa that Arya wants to steal her title as Lady of Winterfell. Sansa knows this is a lie; Arya never wanted to be a lady. Her little sister always wanted to be a knight. The realization that Littlefinger is purposefully driving a rift between the Stark family sets in then. "Littlefinger spreads his hands. Well? There it is. Sansa nods. There it is," the script reads.
And the rest is (throat cutting) history...