This hidden detail in the GoT credits will blow your mind

*Warning: minor spoilers ahead, potentially.*

The seventh season of Game of Thrones kicked off last week with an action-packed episode, including Jon Snow confirming to anyone who would listen that Winter, which has been “coming” for ages, is finally here.

And it seems Winter is bringing a whole lot of problems. White Walker-shaped problems.

While the people south of the Wall probably think they’re pretty safe from the undead army’s advances, considering there’s a big, er, wall in between them, last week’s premiere hinted that the wall isn’t going to stop them.

You’ll remember that the Hound had a vision in the fire – if you don’t, check out the video above.

In it, he described that “where the Wall meets the sea” he saw “the Dead just marching past”.

It all sounded a bit mystical at the time. How could it happen? Unless they magically became able to walk on water, it seemed damn near impossible that they could just stroll into Westeros.

But eagle-eyed Redditor RohitMSasi spotted a glaringly obvious clue before The Hound even had his fiery premonition. In the opening credits no less!

Helpfully pointed out in this infographic, the Redditor shows just how those White Walkers are going to make their way past the wall.

The sea has frozen over because, well, Winter is here!

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So yes, turns out the White Walkers magically can walk on water. Frozen water.

This is bad. Very bad.

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