Game Of Thrones: What Was In The Letter In Season 7, Episode 5? [SPOILERS]

Last week's episode of Game of Thrones offered death, destruction, and a whole bunch of people lit on fire by a dragon. It was everything you could have ever wanted in an episode, and it was the shortest of the series. This week, things slow down a bit, but there's a moment that hearkens back to the first season of the series, involving Sansa and the Lannisters.

Warning: Spoilers are coming.

During "Eastwatch," Arya was keeping a close eye on Littlefinger, and she overheard a discussion about a message, which there was only one copy of. Littlefinger hid the message somewhere in his room, and when he left, Arya broke in and found it inside his mattress.

However, as Arya leaves the room, there is a shot of Littlefinger hiding in the background. He's playing Arya Stark like a fiddle. While the viewers don't get a really good glimpse at the note, we can see that it's signed by Sansa.

Take a look at a screenshot of the note for yourself below:

Here's what we could make out from the note from the screenshot above:

"...is dead, killed from wounds he took in a boar (attack?)...

...Joffrey and tried to steal his throne The Lannister...

...King's Landing and swear fealty to King Joffrey and...

Your faithfull sister, Sansa."

So what's the deal with the note? Back in Season 1, Sansa Stark was to be wed to Joffrey, and Ned Stark--Sansa's father--was Hand of the King to Joffrey's father, King Robert Baratheon. Long story short, the king died, Joffrey took over, and Ned was arrested.

At this point, Cersei Lannister, accompanied by Lord Varys, Littlefinger, and Grand Maester Pycelle, forced Sansa to write a letter to her brother and mother back at Winterfell to keep the peace. Robb Stark did eventually see this letter himself, but Maester Luwin told Robb that it was Cersei's words with Sansa's writing.

This is the first time Arya is seeing the letter or even knows of its existence. She does not know the circumstances of why it was written, and Littlefinger planted it for Arya to find to plant seeds of doubt within her sister. While Arya is intelligent, the last time she was with her sister, Sansa was a bit of a brat and really wanted to marry Joffrey, so she may not see through this like Robb did.

It's obvious that Littlefinger wants Arya out of the picture, but does Arya know she's being played, and if not, how will she confront Sansa about this letter, if at all?