The trailer opens with a shot of Cersei walking towards a giant map of Westeros painted on the floor, with her voiceover talking about how she's surrounded by enemies.
When Cersei mentions "enemies to the east", we get a shot of Grey Worm and the Unsullied in their new winter uniforms.
What's east of King's Landing? Dragonstone (more on that in a sec).
There's a shot of a different map - what looks like the table at Dragonstone - tracking north.
Then Cersei mentions "enemies to the west", and we see this ship. It could be Euron Greyjoy's longship Silence, coming from the Iron Islands in the west.
There's another shot of this map, still heading north.
Cersei talks about "enemies to the south" and we see someone sharpening a blade. Perhaps someone in Dorne?
Then there's this last shot of the map, settling on the Wall and the area north of it as Cersei says "enemies to the north".
The next shot is Arya, who doesn't appear to be in the snow-covered North yet, but is almost certainly headed that way.
And then we get a good shot of Cersei's awesome floor map, as she stands contemplating the North with Jaime looking on.
Are they worried about the King in the North - or perhaps even the Night King?
"Whatever stands in our way, we will defeat it," Cersei says. Her confidence and determination to destroy everyone who is not a Lannister isn't surprising - but it's interesting she says "whatever" not "whoever".
It could mean she's aware of the White Walker threat. Or maybe she's referring to the dragons. Or both. Or just literally everything.
Her words are backed up by a great shot of the Lannister army marching.
Then we see Cersei, with Jaime by her side (sigh) and the Zombie Mountain in front of her (eek), being addressed by someone in the throne room.
It's hard to tell who this is, but it could be Euron Greyjoy (if he's somehow found the time to have a haircut while he was building 1000 ships on an island with no trees). He might be proposing an alliance and/or marriage with Cersei since he quite literally missed the boat with Daenerys.