Game of Thrones S07E05: What the letter Arya found said and what it meant

The latest episode of Game of Thrones had Arya Stark discover a letter that troubled her greatly and may have major ramifications in the story.

It was only onscreen for a moment, but what the letter said and who it was written by are very important.

Spoilers for Game of Thrones S07E05 follow.

In the episode, entitled Eastwatch, a suspicious Arya followed Littlefinger around Winterfell and covertly observed his actions - not knowing that he was aware of this and intending for her to do so.

She followed his breadcrumbs to a hidden letter in his quarters, which was written by her sister Sansa to their older brother Robb way back in season one.

Although the letter was hardly decipherable to viewers, fans have worked out every word and published them online.

"Robb, I write to you with a heavy heart. Our good king Robert is dead, killed from wounds he took in a boar hunt," the letter says.

"Father has been charged with treason. He conspired with Robert's brothers against my beloved Joffrey and tried to steal his throne. The Lannisters are treating me very well and provide me with every comfort. I beg you: come to King's Landing, swear fealty to King Joffrey and prevent any strife between the great houses of Lannister and Stark."

Sansa wrote this under duress, forced to by Cersei and her cohorts under implicit threat of death. But Arya won't know this, will see it as a betrayal of her family, and the seeds of distrust and aggression Littlefinger is sewing between the remaining Stark siblings will develop further.

"[Littlefinger] is looking for a way to prevent this sister bond from developing further, because the tighter they are, the more definitively he is caught on the outside of it," says showrunner D B Weiss in the Inside the Episode feature.

"He knows full well that with what's going on in Sansa's head with regards to Arya and how dangerous she is, when Arya starts to act dangerous and act angry, he knows where Sansa is going to turn."

If Jon Snow doesn't hurry back to Winterfell soon or Sansa and Arya don't wise up to Littlefinger's evil plotting - tragedy will surely strike at the northern castle.

The next episode of Game of Thrones airs in New Zealand on Monday, August 21.

Newshub.