Williams posted a close-up of her battered white sneakers, which were spattered with blood — hopefully stage blood. She included a heartfelt note saying goodbye to her character on the HBO original series, indicating that she has finished filming the final season once and for all.
"Goodbye Belfast. Goodbye Arya. goodbye Game of Thrones," she wrote. "What a joy I've had. here's to the adventures to come."
Because Game of Thrones is infamous for filming things out of order, Williams' late exit from the set did not necessarily give away anything about the plot. However, some fans took her hashtags very literally.
"Last woman standing," read one tag. "Barely," added another. Fans flooded the comments section, debating whether this was a slight tease or a literal giveaway of the plot of the upcoming season.
If that weren't enough, Lena Headey — the actress who portrays Cersei Lannister herself — dropped another leading comment.
"QUEEN," she wrote. She included a crown emoji, followed by a string of raised hands and kissy-faces. This set fans on a speculation spiral. While chances seem pretty slim that Arya Stark will end up sitting on the Iron Throne, she is a fan favorite, and many can't help but hope.
Headey's comment was like a catalyst for that faint hope. Williams' followers went berserk with their guesses, giving serious credence to the idea.
"So... did jaime kill u already?" one person responded to Headey.
"Did she just give the whole freaking ending away?" another person wrote.
"Hope that's Cersie's blood!!!" added a third.
Of course both Headey and Williams — like the rest of the cast and crew of the show — are under strict guidelines as to what they can and cannot reveal. The actors could tease small details in subtle, imperceptible ways to stir up intrigue, but giving away the ending of the series would violate their non-disclosure agreements.
The show is also notorious for misdirecting fan speculation. As one commenter pointed out, Williams herself worked to convince fans that Jon Snow would not be returning from the dead after season 5's brutal cliffhanger ending. Bearing that in mind, it is dangerous to put too much weight on any revelation made by the cast on social media.
Game of Thrones is set to return for its eighth and final season at some point in 2019. Producers have yet to reveal an official premiere date, though according to the fan site Winter is Coming, they are within days of wrapping up on filming. The season will have only six episodes, though each one is expected to be longer than the usual one-hour run time.