"The Watchers on the Wall," the ninth episode of Game of Thrones' fourth season, is a Westeros rarity since all the action happens in and around a single location as the Wildlings attempt to take control of Castle Black. The Neil Marshall-directed hour also has most of the show's sprawling main cast sitting this one out, instead focusing on Kit Harrington's Jon Snow, John Bradley's Samwell Tarly, and Rose Leslie's Ygritte, as they lead their warring factions — the Night's Watch and the Free Folk, respectively — into battle up, down, and all around the Wall.
The final result is a gripping hour of television that quickly dispenses with dialogue and leaps headfirst into a visually stunning 31-minute battle sequence, the season's special effects centerpiece that rivals any feature film in terms of sheer scope or CGI wizardry.
To discover how all of the disparate elements came together, director Neil Marshall — who also helmed Season 2's equally stunning "Blackwater" — broke down his Emmy-nominated Game of Thrones episode for BuzzFeed.
Warning: Spoilers for "The Watchers on the Wall" below, if you've yet to see the episode.
From start to finish, Marshall had nine weeks to complete the episode, with four weeks solely dedicated to pre-production (versus the seven days he had on "Blackwater"). "I definitely needed it this time," he wrote to BuzzFeed of the additional weeks, which were dedicated to — among myriad other duties — laying out a concise plan of attack for the relentless battle, conceptualizing the computer-generated mammoths, and choreographing an intricate 360-degree crane shot of the Castle Black courtyard, mid-fight.
The three-week shoot took place in Belfast, Ireland, with Castle Black erected in a huge quarry just north of the city, and a few additional days spent in a green-screen studio doing elements and motion-control work, according to Marshall. And it should come as no surprise that, given its 31-minute running time, two of those three weeks were dedicated to filming the epic battle.
Building the mammoths
"The mammoth, we just wanted to look as huge and authentic as possible," wrote Marshall in an email to BuzzFeed about designing the prehistoric creatures, which were entirely conceptualized before shooting commenced. A lengthy pre-visualization processes was also conducted where the entire battle sequence was animated so the various behind-the-scenes departments had a frame of reference from which to work. "This very crude animated version served as a living storyboard which we based all our living action plates on," he added. "It's a long procedure, but it becomes invaluable when trying to map out and then construct a sequence like this."
Once pre-production was completed, Marshall and his teams set out to bring their vision to life. No easy feat, considering the number of complex elements at work. "Given that these scenes involved multiple elements — the live-action plates, the giants (real eight-foot tall guys shot against green screen), and the mammoth itself, 100% CGI — making sure when you add these elements together they line up correctly ... these were easily the most complex scenes I've ever shot," he explained.
Marshall revealed that a huge green frame stood in for the mammoth on set, and that it was "moved by four guys in green Lycra suits at each of its legs." After rehearsing with the makeshift mammoth, ensuring none of the actors crossed the animal's path, the director "shot the rehearsal as a reference, then shot the exact same action without the frame, just the empty space, which the CGI mammoth would be composited into."
For Marshall, the mammoth was the biggest question mark of the entire episode. "I know that the creators of the show wouldn't allow anything less than a 100% convincing mammoth," he wrote, adding, "I'm very grateful for having such brilliant VFX supervisors around to make sure it was going to work. And it so did!"
Jon Snow enters the fray
Jon Snow leaving his post atop the Wall and joining the battle is Marshall's favorite scene of the episode. "It's felt like Jon's been a lion kept on a leash for the entire series, and now he finally let off the leash — and mayhem ensues," wrote Marshall.
"It feels like a really satisfying moment dramatically," he continued. "This is Jon not only assuming leadership but leading by example, but obviously it leads to one of the most heartbreaking moments of his life. So it's a scene that works on multiple levels beyond just being some very stirring action."
Circumnavigating the castle
Halfway through the battle, a sweeping 360-degree shot serves as a locator for all the characters as they wield swords, bows, and hammers. It's a masterful shot that Marshall still can't actually believe he was able to execute.
"As soon as I saw the set for the first time I knew I wanted to pull off a 360 shot — the set and action were just screaming for it," he wrote. "So I devised a shot that would visually link all the major characters and clearly establish where they were at this particular point in the battle. I think geography is vitally important in a action sequence. It's all too easy to lose a sense of where characters are in the blaze of quick cuts and physical action."
"Having a shot like this that binds all the characters and their actions together really helps the audience understand what's happening, so they remain involved in the scene," he explained. "We blocked the shot and rehearsed for about an hour or two, then got it in seven takes."
"Once we pulled off the 360 shot, the entire crew gave themselves and each other a big round of applause, and it was well deserved. It's such a great cast and crew regardless, but for that particular shot it was like everyone — from the stuntmen and extras to the crane operators to the assistant directors — understood what we trying to achieve and were absolutely at the top of their game that evening. That nobody got hit by the camera, which was sweeping past their heads at incredible speed, was a miracle in itself. But everyone had their timing and moves down to perfection and that's why it only took seven takes. That was a great moment."
Saying good-bye to Ygritte
When asked which scene he's proudest of, Marshall cited Ygritte's death scene. "It's an important responsibility for a director to handle the death scene of a major and much-loved character like Ygritte," he responded. "The writers have invested a lot of heart and soul into creating and building this character and giving the audience time the time to really come to care for her. So I certainly feel that responsibility, both to the writers and the fans."
Logistically, however, the timing of her death presented a unique problem. "I had to overcome the issue of these two characters having such a painful and intimate scene within the context of a battle," he added. "I achieved this by using slo-motion — one of the very few times it's been used in Game of Thrones, one of the other times being the file of my previous episode, 'Blackwater' — in order to visually and aurally force the battle into the background, leaving them almost trapped in this moment, allowing it to play out in a more poignant manner and pack a more powerful dramatic punch."
The impact of Ygritte's final moments can not be understated. Turns out, fans — and Jon Snow — weren't the only ones overcome by grief at this loss. "Killing off Rose's character was a very emotional moment, both on and off screen," wrote Marshall. "I've done plenty of movies where characters get killed off, and it's always a sad time, even if you've only spent a few months or even weeks working with these people. On a TV series, it's more like years! So as emotional as it was for me, it was 10 times worse for the cast and crew who'd worked with Rose for two or three years. There were certainly a few tears shed that night."
Ending the battle
Before dawn, the Night's Watch is able to stave off the Wildings through perseverance, sacrifice, and an enormous scythe that renders enemy climbers obsolete. "The scythe was very similar to the mammoth in that it was 100% CGI," Marshall shared. "I shot all the live action elements — the man releasing the scythe mechanism, the Wildlings on the wall about to be struck by it — but all the actual scythe shots were created in the computer. And beautifully realized they were too."
The visual impact of that final blow serves as a striking bookend to the astounding sequence, and one of the show's most indelible images. In the end, Marshall's second Game of Thrones episode not only trumped his first, but put "The Watchers on the Wall" near the top of his list of professional achievements.
"Every director would love to have had more time, but that's just not how it works — especially on TV," he wrote. "You have to learn to work fast, which I did, and so I'm very happy with everything I did on this episode. I'd never say 100% happy, but certainly not far off!"