WATCH: GoT fans spot 'mystery ghost'

SPOLIER ALERT: If you have not seen the most recent episode of Game of Thrones season seven then do not read any further... Unless you want to know what happens. In that case, go ahead!

Fans of Game of Thrones are not-so-subtly freaking out after spotting a "ghost" in a scene from the latest ep.

After long-suffering viewers were finally given a Stark family reunion with the remaining (also see: alive) members of the family, a mystery figure in the background has prompted fans to speculate a major character is about to hit up Westeros. Watch the clip of the scene above.

With Arya Stark finally returning home to Winterfell during this week's episode The Spoils of War, and hugging it out with Sansa and Bran, she caught up for a chat with Brienne of Tarth, hoping to show off her newly-acquired sword fighting skills.

It was while showing off her #skillz, Arya was quick to remind Brienne that she "swore to serve both my mother's daughters". Remember her mum? Catelyn Stark?!

It is at ~exactly~ that moment where Arya brings up her mother that Reddit user GrennsGal pointed out that a ghostly figure strolls casually in the background.

GrennsGal points out that: "At the word MOTHER you can see a woman in a long green dress w/ long auburn wavy hair with her head down walking past the background gate, resembling Cat."

ICYMI: Cat was caught up in that unfotunate Red Wedding business and watched her son, King Robb, his pregnant wife Queen Talisa, and their crew get murdered, all arranged by king jerk Lord Walder Frey, before she had her own throat slit by "Black" Walder Rivers back in season three. It was a lot and honestly we are still grieving.

So has Catelyn Stark done a Jon Snow and returned from the dead?

Super fans would know that Catelyn's return is a major storyline in the George RR Martin novels, however it is yet to be addressed in the series.

In the novels Catelyn comes back to life and returns for vengeance as, well basically a zombie, by the name of Lady Stoneheart, ready to kick the butts of anyone associated with the Freys, Boltons, or Lannisters. Lady Stoneheart also plays a big part in Brienne and Podrick's storyline.

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So if you're wondering where Arya gets her vengeance streak from, I think we've pin-pointed it.

GoT showrunners David Benioff and DB Weiss have previously spoken about their decision to not bring Lady Stoneheart to the screens, a decision George was not here for.

"That was probably the first major diversion of the show from the books and, you know, I argued against that, and David and Dan made that decision," the author told Time.

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