Did you spot this important Easter egg in the new Game of Thrones title sequence?
Something's changed on the map of Westeros...
Winter is coming, there seems to be no arguing with that, and with it come the White Walkers and their army of the dead. But exactly how will the Night King and his hordes of wights get past The Wall, which has protected Westeros from them for so many centuries?
There are a few theories – including the use of a magical horn that will bring the Wall down and the fact that Bran has been marked by the Night King, which may allow his army to thwart the spells that have kept them from passing through at one of the entrances – but it's looking increasingly like there is an even stronger contender: that the White Walkers will simply walk around The Wall, on its east side, after the sea is frozen solid.
We've already looked at how a deleted line of dialogue – "the waves are frozen" – from the Hound's account of the vision he had in the season seven opener may have hinted at that solution, and now we've spotted some more evidence to back it up, in pretty much the first place we should have looked, the show's opening credits.
As you may have noticed, that swooping journey around a 3-D map of the Seven Kingdoms and beyond changes slightly from season to season, and this time there's a pretty significant difference in the vicinity of The Wall.
Here's The Wall in the credits from an earlier season of Game of Thrones...
And here it is this season...
Can you spot the difference? We've added a big arrow to help you out. That's right, the sea appears to be frozen.
We don't yet know how this has happened – whether it's due to the Night King's magic or simply that the 100-year winter is going to get so cold that the sea will freeze naturally – but since there is good evidence that the map is an account of the history of Westeros, it seems likely it is going to happen.
"Ice. A wall of ice. The Wall. It's where The Wall meets the sea. The waves are frozen. There's a castle there. There's a mountain, looks like an arrowhead. The dead are marching past. Thousands of them..."
Brrrrr! Yep, winter is coming alright, and it looks like it's coming by sea...
Game of Thrones season 7 is on Mondays on Sky Atlantic and NOW TV at 2am, repeated at 9pm