Warning: Spoilers ahead for HBO's "Game of Thrones," including speculation of future events.

One of the best sequences on Sunday's "Game of Thrones" season seven premiere was an extended scene featuring Sandor "The Hound" Clegane, Thoros of Myr, and Beric Dondarrion.

The slow-paced scene had Sandor confronting his past in more ways than one while also forcing him to look (literally) at the future.

Thoros asked Sandor to look into the flames of a fire to see a vision from the Lord of Light. To our surprise, Sandor did see something in the flames: the Wall.

"It's where the Wall meets the sea," Sandor said. "There's a castle there."

This is, of course, Eastwatch by the Sea, one of the Night's Watch castles and the same one Jon Snow asked Tormund to go defend with the Wildlings.

But thanks to HBO's official "Game of Thrones" season seven premiere recap, we have an additional piece of important dialogue from Sandor's fire-reading. Here's a what the "Game of Thrones" website wrote in its synopsis of the episode:

"The waves are frozen" wasn't a line in the episode. HBO

The HBO transcription of the scene has an added line of dialogue that was most likely cut from the final edit of the episode: "The waves are frozen."

This could be huge. Sandor specifically says he sees Eastwatch by the Sea, and we know the Night King was last seen at Hardhome, just a short distance from Eastwatch. Here's a map of that area:

Eastwatch is right next to the sea — hence the name. HBO

We know the Wall is imbued with magic that prevents White Walkers from passing. Fan theories suggest that Bran might ruin that soon, but in the meantime, you might have been wondering how the Night King's army could cross into Westeros.

Frozen waves could do the trick.

If the ocean near Eastwatch by the Sea freezes, then technically the Night King and his army could just walk around the far border of the Wall, right?

The Night King walking on water is a terrifying prospect. Helen Sloan/HBO

We're curious as to why the line about frozen waves was cut from the show but remains on HBO's site. Will we get hints of the Night King's movement again in the future? Were the showrunners perhaps saving that dramatic visual for a battle later on in the season?

Another mystery from Sandor's fire-vision is the mountain he referenced.

"There's a mountain — looks like an arrowhead," he said. "The dead are marching past. Thousands of them."

So far on the show, we haven't seen a mountain that looks like an arrowhead, but this is another visual cue fans should look out for. Some think the mountain he saw was "The Mountain," the nickname of Gregor Clegane. Perhaps this is one more tie-in to the "Cleganebowl" theory, though we believe it was a reference to the geographical landmark and not Sandor's undead brother.

For more moments you might have missed, read our breakdown of six important details from the season seven premiere.

Episode two, "Stormborn," premieres Sunday at 9 p.m.