'Game Of Thrones' Season 4, Episode 9
What can fans expect from "Game Of Thrones" Season 4, episode 9, "The Watchers on the Wall"? HBO

The "Game of Thrones" Season 4, episode 9, "The Watchers on the Wall," preview gives viewers the first look at the battle at Castle Black. Much like the battle between the Red Viper and the Mountain in last week's "The Mountain and the Viper," the attack by Mance Rayder's army has been a highly anticipated event.

Warning: Full "Game of Thrones" Season 4 spoilers ahead.

Per the "Game of Thrones" Season 4, episode 9, synopsis, "Jon Snow and the Night’s Watch face a big challenge." While the synopsis does not reveal a lot for Sunday, fans should know what to expect from the penultimate episode. In "Game of Thrones" Season 1, Ned Stark is beheaded, Season 2 featured the massive Battle of the Blackwater and Season 3 saw the shocking Red Wedding,

For "The Watchers on the Wall," the "Game of Thrones" series has selected Neil Marshall to direct the episode, much like he did for "Blackwater." Marshall has a great eye and knows how to film a massive action spectacle. The Battle of Castle Black, which has been brewing since Season 3, will rival the size and scope of the Battle of the Blackwater and could be a rare triumphant moment for the "good guys."

Jon Snow has been warning the Night's Watch about the size and threat of Mance Rayder's army throughout "Game of Thrones" Season 4, most recently in "The Mountain and the Viper" following the raid on Mole's Town. With the raiding party arriving from the south and Mance 's army from the north, the Night's Watch have no choice but to defend the wall but there are less than 200 Brothers but thousands of Wildlings.

In "The Watchers on the Wall" preview, viewers get a small glimpse of the size of Mance's army including what appears to be a mammoth as well as a giant trying to break through the Wall. Love is another important theme in the "Game of Thrones" Season 4, episode 9 preview and it looks like Jon Snow and Ygritte will meet as foes.

"The Watchers on the Wall" preview can be viewed below. "Game of Thrones" Season 4, episode 9 airs on Sunday at 9 p.m. EDT on HBO.

Warning: "Game of Thrones" spoiler discussion, don't read if you have not read "A Song of Ice and Fire" or don't want Season 4 spoiled.

- Can fans really deal with another emotional moment? With last week's death of the Red Viper, "The Watcher on the Wall" will feature Ygritte's death. Fans may not be so attached to the character, but it's going to be painful to watch Jon Snow see the one, and only, person he has ever loved die.

- While all the focus will be on the Battle of Castle Black, I wonder what other storylines will be covered. It makes sense to see what Stannis has been up to, and to catch up with Bran, and the episode will also include the aftermath of the trial by combat. There are a lot of storylines to tie up or get in place prior to the "Game of Thrones" Season 4 finale.