This moment was quickly made in to the GOAT downvote gif on reddit

The fifth and final utterance of Ygritte’s trademark line

The dialogue is slightly different in the books, where Jon, in desperation, says he’ll get a medic who can heal Ygritte

We very, very rarely do slow motion. We don’t like slow motion, it tends to feel self-conscious to us and a little bit cheesy, but this one shot we loved so much there was no way…when we say in the director’s cut that Neil had put it in slow, we loved it.
- David Benioff (co-creator of the series and writer of this episode)

There was one scene I remember watching and we said, “Rewind, somebody put that weird speed up, you know like a speed ramp, on Kit’s sword move there and it looks fake, it looks too fast. Can we fix whatever somebody did to that shot?” And Chris, the visual effects editor looked at it and he said, “There’s no speed ramp on this shot. Like, that’s the speed at which he’s moving with this big heavy aluminum sword.”
- D.B. Weiss (co-creator of the series and writer of this episode)

We have these actors that we love: Josef Altin as Pyp and Mark Stanley as Grenn. While neither of the characters die in the books, it felt like we had to have some casualties amongst the people we really care about here. We decided it should be Grenn because Grenn is someone that we’ve seen from quite nearly the very beginning of the series and he’s always been around, he’s quite loyal and steadfast. We knew that people would care about him, you know, down there and it’s a great scene. We love seeing him really take command in his final moments and stir his comrades to courage
- David Benioff (co-creator of the series and writer of this episode)

Check out the evolution of Grenn, from Grenn to Grenn the Giantslayer

As this episode focuses only on Castle Black, it’s the third episode in the series which doesn’t contain a single scene in King’s Landing

The first being Season 1 Episode 2 “The Kingsroad” and the second being Season 3 Episode 9 “The Rains of Castamere”

This episode is a reference to the words of the oath sworn by new recruits of the Night’s Watch

I am the sword in the darkness. I am the watcher on the walls. I am the shield that guards the realms of men.

It was directed by Neil Marshall who also directed “Blackwater”, Season 2’s epic 9th episode (the one with the AWESOME explosion)

The episode premiered to 6.9 million viewers, up against heavy competition with the NBA Finals, Tony Awards, and the Miss USA Pageant