Stannis Baratheon attacks King's Landing! That's the entire storyline this episode. We don't go to the Wall, we don't go to Qarth, we don't check in on Arya or Theon or anyone. If you're not in King's Landing or attacking it, you don't get to be in this episode.
The overall attack is stopped, thanks to Tyrion's boat full of wildfire and a timely speech that comes right after Joffrey abandons the defense of the city. Even so, Stannis is about to win when Tywin Lannister rides in and saves the day. Cersei was about two seconds from poisoning Tommen, so it's a good thing she spent a long time telling a story about lion cubs.
During the battle, the Hound has a flashback to the time his face got burned and decides to give up the whole deal. He walks out on the battle, which is probably a good idea. Out in Stannis's fleet, Davos and his son aren't so lucky, since they're on the boat closest to the giant explosion. I mean, they might have survived, but I wouldn't bet on it.
According to the pre-show content advisory screen, there will be both graphic violence and nudity tonight. That's officially a warning, but it's really the sort of thing you'd put in all your advertising if you could. In fact, the graphic violence is the big selling point for tonight's episode. So let's get graphic!
The opening credits do not contain any graphic violence, so they're already disappointing. Not even any non-graphic violence, in fact. They do contain King's Landing, Harrenhal, Pyke, Winterfell, the Wall and Qarth. But really the only place we're going to is King's Landing. I was kind of hoping the credits would just stay in the one location the whole time, but I guess they'd need to make a special animation that takes five times as long to show the city.
A boat sails through the night. Well, it's technically sailing through water, but what I mean is that it's nighttime. And there are several more boats behind it. Sailors do all sorts of sailor-y things while men in armor sit and wait. One man stands up and vomits into a barrel and he's not the first one. We know that because the barrel overflows, which seems like exactly the sort of thing you don't want happening in front of you when you're seasick. Davos and his son Matthos stand on deck and discuss the situation. The tide's against them, but they have the wind, which will send them straight to the gate. Matthos thinks Davos is going home, but he hasn't lived at King's Landing in years. He's historically avoided the Royal Fleet so he finds it odd to be sailing directly toward them. Matthos points out that, technically, they're the Royal Fleet since (by their lights) Stannis is king. Stannis says there's more than one Royal Fleet at the moment. Matthos is confident that the battle will go well and that Stannis will sit on the Iron Throne with Davos as his Hand. I guess it's possible. He also wants to put Joffrey's head on a pike, which I can't say I'm opposed to. Although Joffrey hasn't really done much to Stannis aside from have the wrong father. I guess when you want to be king you're kind of obliged to kill the current king just as a matter of principle. If Joffrey were smart, he could wait until Stannis got within head-chopping range, and then claim that he's a victim of his evil mother and never wanted to be king. But I guess Joffrey's not one to sit around planning elaborate ways he could surrender safely.
Back on the boat, Matthos gives us some exposition: Stannis's fleet outnumbers Joffrey's ten to one and his army outnumbers Joffrey's five to one. Davos is more cautious, reminding him that the walls of King's Landing have never been breached. Enough talk! Let's get to some graphic violence already! We get it. Davos's kid has faith in the Lord of Light and in Stannis and in all that stuff.