'The Mountain And The Viper' Recap Video
The latest "Game of Thrones" Season 4, episode 8, "The Mountain and the Viper," recap video focuses on Castle Black and the Wildling army. HBO

There have been few clues about what to expect from "Game of Thrones" Season 4, episode 9, "The Watchers on the Wall" other than it will focus on the Battle of Castle Black. An interview with series creators David Benioff and D.B. Weiss, a new recap video and a French preview for the episode gives viewers a glimpse of what to expect from the penultimate episode of "Game of Thrones" Season 4.

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

Viewers knew "The Watchers on the Wall" was going to feature a massive battle as Neil Marshall was set to direct the episode. Marshall previously directed "Game of Thrones" Season 2's "Blackwater" and it made sense for him to film another complex action-heavy episode. The Battle of Castle Black as been brewing since Season 3 and Mance Rayder's Wildling army is finally at the gates of the Wall and the Night's Watch has no choice but to fight.

As for the scale, Benioff and Weiss say the Battle of Castle Black will be the biggest to date on the show. Speaking to Entertainment Weekly, Benioff said, "I wouldn’t say it’s wall-to-wall action -- because it doesn’t start right away -- but once it gets going about 15 minutes into the episode it doesn’t stop." The series creators discuss the challenges of shooting such a large battle scene, including creating bigger sets and relying on visual effects that would not be completed until after filming had wrapped up.

While the U.S. was treated to a short preview for "The Watchers on the Wall," France gets an extended version, which includes a few new shots of the battle. The OCS City generation HBO trailer includes a few extra shots of the battle. The trailer has its fair share of spoilers for the episode and the battle so don't watch if you want to remain suprised.

Speaking to Access Hollywood, Kit Harrington (Jon Snow) discussed the difficult schedule and said "The Watchers on the Wall" was the most expensive "Game of Thrones" episode yet while promo photos for the episode on Winter Is Coming also feature plenty of Jon Snow. According to Entertainment Weekly, the entire "The Watchers on the Wall" will be dedicated to the Battle of Castle Black which means fans will have to wait until the "Game of Thrones" Season 4 finale to learn about Tyrion's fate following the end of "The Mountain and the Viper."

HBO also released a new "Game of Thrones" Season 4, episode 8 recap video which summarizes what happened in Season 3 and the more recent events. "The Watchers on the Wall" airs on Sunday at 9 p.m. EDT on HBO.