Last night Game of Thrones fans were treated to very possibly the best episode ever.
But amid the blood and carnage of the Battle of Winterfell, one fan thinks he might have spotted a key moment that most missed.
Now, before we go on, there's no getting around it, this article contains spoilers, so either stop reading and come back when you have seen the episode or be prepared to have the series ruined.
Ok, so, how did Arya really kill the Night King? It's a question everyone has been asking since she plunged the dagger into his chest and saved EVERYONE.
But how? Well, one eagle-eyed GOT fan thinks he spotted the young Stark girl using her powers of disguise to hide among the army of the undead.
How did Arya kill the Night King? Credit: HBO
Sharing his theory on Twitter, the fan wrote: "Arya didn't jump over a ton of white walkers, she was wearing the face of one, hence melissandre: 'brown eyes, green eyes, BLUE EYES.'"
They then shared a short clip showing the - blink and you'll miss it - moment, with the caption: "This includes the clip of the White Walker glancing. That glance made me think Arya was wearing its face."
Now, maybe you're one of those who has just dipped in and out of the series over the past few years and have no idea what we're talking about.
When Arya was younger, she was trained by Faceless Man Jaqen H'ghar, one of the deadliest assassins in all of Westeros.
He taught her how to become 'invisible' and get close enough to her enemies and kill them - a power she used to great effect to kill Walder Frey for his part in the Red Wedding.
But Arya wasn't the only woman who kicked a serious amount of arse during last night's battle - Lyanna Mormont was a total legend.
The diminutive Lady of House Mormont took her final bow in this latest episode, but with her final act she cemented her place in folklore and proved once and for all that she's one of the baddest MFs in the whole of Westeros.
Charging straight at a giant that had been turned into a soldier in the Night King's army, she had her bones crushed in one grasp of his mighty paw.
Featured Image Credit: HBO