Recap (with spoilers)
One would presume that the title of the episode refers to the Night's Watch, the group of rapists, murderers and thieves who have been exiled to lifetime service near a 1,000 foot Wall of snow and ice ostensibly protecting the rest of Westeros from the frozen horrors (blue-eyed, re-animated corpses known as White Walkers) and uncivilized individuals (called "Wildlings) that exist "beyond the Wall." In fact, for people who have read the books, we know that the phrase is used at a funeral for a Brother of the Night's Watch. In fact, during this episode we see Lord Commander Jeor Mormont (and the entire company) saying these words as the dead body of a fallen brother is set afire. By the end of the episode we see that it is Mormont's own watch that will be ended. Mormont is literally stabbed in the back by some of his own treacherous Brothers who have grown tired of starving and freezing while watching a "daughter-fucking, Wildling bastard" (and self-proclaimed "Godly man") stay warm and eat heartily.
But a mutiny among a group of dishonorable men is most definitely not the most important event to happen in S3E04, but it is probably the event that will have the most impact on Westeros, because it demonstrates that the organization that has been dedicated for millennia to protecting the rest of the continent from the northern terrors is unlikely to be able to do so, and "Winter is coming."
There are so many highlights to this episode but the first one I want to talk about involved Varys. Varys is a eunuch, also known as the Lord Of Whispers or The Spider who is an undisputed powerhouse in King's Landing (the site of the Iron Throne and the unofficial capital City of Westeros) and a member of the 6-person Small Council where ultimate power resides. Varys is one of my favorite characters in the books (closely followed by Tyrion Lanniser, Jon Snow, Arya Stark, Brienne of Tarth and (of course) Daenerys Targaryen). On the show Varys is played by Conleth Hill with mesmerizing power and pitch-perfect mystery. Even though he is intimately involved with some of the most significant events that happen in the books, Varys has never had a chapter named after him and the story is never told from his perspective. On the show, however, the producers have wisely decided to use their precious minutes of screen time to put Conleth Hill's Varys on the screen.
In this episode, Varys has a scene where he explains to Tyrion how he was "cut" i.e. became a eunuch which is absolutely blood-chilling. But, he also gets a second scene where he shares information about Littlefinger (whom he calls the most dangerous man in Westeros) with the infamous Queen of Thorns, Olenna Tyrell, played with delicious aplomb by Diana Rigg. Varys and Olenna are extremely skilled players at the Game of Thrones, and the moves that they make together will reverberate throughout the cast of characters.
The second highlight that I must talk about is of course the final scene where Daenerys "sells her dragon" in order to purchase a slave army of Unsullied. This is a great triumph for Emilia Clarke, who completely dominates the screen as she recites unintelligible words (in HIgh Valyrian) to command her slave Army to rise up and kill their former slave masters while her dragon does what dragons do, which is breathe fire and kill people. It is one of the high points of the entire series, and it is depicted very effectively and powerfully on the little screen.
The only low point of this episode was the continued thread with Theon and his savior/betrayer. In the books, Theon is a pitied and pitiable character, punished horribly after falling into the hands of a vicious sadist. But the portrayal of his story arc just appears confusing at this point, and this is from someone who has read the books relatively recently!
I think this episode was very good, but not as transcendent as last week's "Walk of Punishment." What is nice is that there is so much story packed into the source material that every single episode for the rest of the season should have at least one major, important event and some may have more than one. For example, it looks like in S3E05 we will discover that not everyone who worships R'hllor, the Lord of Light, is as evil as Stannis' Red Priestess Melissandre.