HBO has released a preview of 'Game of Thrones' season eight episode three.

"The most heroic thing we can do is look the truth in the face," Sansa says at the beginning of the trailer.

It shows the cast prepping for an epic battle. Catapults are prepped as Grey Worm puts on his helmet.

Arya runs from something, Jon Snow looks horrified, Theon draws a bow and the newly knighted Brienne of Tarth rallies the troops.

"The Night King is coming," Jon says before Daenerys declares: "The dead are already here." 

ALSO READ: 3 talking points from Episode 2 of Game of Thrones Season 8

Here is what we know about next week's episode:

It's really long

It will be over 80 minutes (1 hour, 22 minutes) long. This makes it the longest episode in the series history. Following episodes will run for:

  • Sunday 5/5 - Episode four (1 hour, 18 minutes)
  • Sunday 5/12 - Episode five (1 hour, 20 minutes)
  • Sunday 5/19 - Episode six (1 hour, 20 minutes)

There will be an epic battle

Expect to see the longest battle in the history of TV. "In the third episode of the last season, there is a battle that the creators intended to be a historic moment in television," Night King himself (Vladimír Furdík) said at a fan convention in Hungary, according to site SorozatWiki.

"It's brutal. It makes the Battle of the Bastards look like a theme park," Peter Dinklage told Entertainment Weekly.

Battle of Bastards' episode on "Game of Thrones"

The battle reportedly took around 55 nights to shoot. It was directed by Miguel Sapochnik, who famously helmed "Hardhome," "The Winds of Winter," and "The Battle of the Bastards."

Your favourites are going to die

Reports say this epic battle will feature most of the characters. According to EW's James Hibberd, several "beloved heroes" will die in the third episode of season eight.

Get ready to say goodbye to a few familiar faces.

The third episode of Game of Thrones' final season airs Sunday, April 28 on HBO.