Sunday, April 13, was a huge night for "Game of Thrones"; the now-iconic episode has us still freaking out and cheerfully celebrating.

(SPOILER ALERT if you haven't seen Season 4, Episode 2 "The Lion and the Rose.")

In "The Lion and the Rose," also known as the Purple Wedding, one of the greatest moments in "Game of Thrones" history occurs when King Joffrey Baratheon drops dead. He's mysterious killed, likely by poison, and the episode ends with a terrifyingly crazed Cersei screaming for the arrest of Tyrion.

HuffPost TV caught up with Alex Graves, who directed the episode -- as well as this season's Episode 3, Episode 8, and the finale -- to hear about how he approached the epic twist, what else is to come this season, and who we're supposed to hate now that Joffrey's gone.

This is a huge episode with a huge the twist that comes so suddenly at the end. How did you approach it?

With a huge amount of pressure on my back. You walk in knowing that you’re doing something that should be iconic. I was sort of saved by how good the script was because you can really focus on what you’re supposed to be focusing on, which is the characters, the story, and have it presented. That saved me because I got so obsessed with what I was doing that I forgot I was doing something really important. It was really about making sure that no one saw it coming and that there was a growing suspense with the episode.

By opening with the dogs, I wanted the dogs to have a kind of operatic quality so you have the sense that something bad is coming. Then the scene develops at the wedding feast just to make it feel like something’s coming and that it’s really going to be all about Tyrion and possibly Sansa, and that Sansa might be in danger, or that Oberyn’s behind it. Or just misdirecting, logically, the audience from what is about to occur, while at the same time carefully hiding -- in the episode, if you watch back -- sort of the progression of the murder as it takes place. In other words, you’re seeing the murderer do it and you don’t know it.

So you think that if we rewatch the episode, we’ll be able to catch who the murderer is?

No, if you watch it again you won’t catch it. But if you analyze it, and you know who did it and how they did it -- which is another whole thing -- it tracks. And that’s all I can say.

Is the mystery of who killed Joffrey going to be resolved soon or play out all season?

You find out in the season is all I’ll say. And also, the thing I would say about Joffrey’s death, like any death on “Game of Thrones,” it’s an end, but it’s also a beginning of a story. The same with Ned Stark’s beginning.

It’s such a big way to start off a new season and sets a really high bar for what’s the come for the next eight episodes. Will there be more just as shocking moments?

Well let me just say this, I directed four episodes [this season] and number two [“The Lion and the Rose”] was the smallest episode. Wait till you see episode 10. The finale is really a finale. It’s not the episode after episode nine, it’s the big one.

What can you say about how dark this season will get? Any words to prepare us?

The thing I think about the season that’s the most interesting that I realized about a third of the way through was that it’s moving from the politics of power to the politics of who isn’t. The bad guys have been in control for such a long time that things are so bad that something’s gotta give, and there’s an enormous fracturing that happens in this season that is going to completely surprise you, episode by episode, and none more so than the finale. Just reading the scripts are a blast, you just start to go, “Oh my god, this is the season to end all seasons.” The scripts are just amazing.

How much creative room did you have compared to what was written in the scripts?

I had a lot of room, I mean the scripts aren’t changed and you don’t want to change them. They’re just a full steak dinner for a director, but at the same time you are presented with, “Okay, how are we going to do this?” Everybody has their ideas, but I certainly was allowed to shoot, and direct, and cut it. They want me to direct, they like the way I direct that’s why they hire me [laughs].

You also directed next week’s episode, “Breaker of Chains.” What can you tell us about that?

Daenerys’ story really kicks in a big way in episode three. That was a case of a real starting from scratch. We had the script, we knew what happened, we had the dialogue, but it was like where in the world and how in the world are we going do this sequence? That was a real blast, it was like making a movie, you’re starting from nothing. We do this huge sequence and I had done, last year, The Plaza of Pride where Daenerys’ dragons take over the plaza, and this sequence [in episode three] is actually twice as big as that. And yet, when we did The Plaza of Pride we had a set from an old Ridley Scott movie, we had a lot of stuff we could use, yet in episode three [of Season 4] in the locale that she comes into we had nothing. It’s basically the largest city she’s ever gone to and the biggest challenge she’s ever had, yet there was no set for that. That was fun, but I won’t say anymore than that.

What would you say is the most challenging episode you’ve shot between the two you did in Season 3 and the four in this season?

There’s no question, the most challenging episode was Episode 10 [of Season 4]. Not only because it’s by far the largest episode that they’ve ever made, but the tectonics and the story are the largest that have ever happened, and that’s not counting the x-number of battle sequences, x-number of gigantic digital effects sequences, and x-number of how many characters are alive and standing and even on the continent when it’s over. It’s a big one. The other thing I’ll say is that every time we went into to do a scene from Episode 10 it was harder, and there was a lot more conversation, a lot more growing pains because things are really beginning to change and it was in the writing. People were having to go places they’ve never gone and did things they’ve never done in extraordinary circumstances. It was really hard and really fun.

Now that Joffrey’s dead, the series’ biggest villain, who will we focus all of our hatred on now?

I can’t tell you that. But I wouldn’t be real worried about that fact that there’s no villains, I wouldn’t be too worried about there not being enough trouble on the show.

Would you say what happens this season is going to be more shocking than the Red Wedding?

No, I would say that the events in this season are more surprising, and frankly, more entertaining. It’s a little bit more of an adventure this year and I think part of it that the good guys have a couple of moments and the bad guys have a couple of hiccups.

Is Joffrey’s murder in the episode accurate to the books?

Yeah, it’s actually really accurate. I think the thing that’s throwing people is that Season 3 is part one of that book and Season 4 is part two of the book, give or take. So it’s actually happening in the story the way it happened. In other words, it is actually the catharsis that kind of follows the Red Wedding.

For those who have read the books, would you say that they’re not going to know what to expect this season or will be able to predict it?

I actually don’t think that they’ll be able to predict because the second half of the season kind of mixes and merges into a very interesting cocktail of some of books four and five. So it was really like, “Oh wow!” It was really brilliant the way they did it.