SPOILER WARNING: This article contains major spoilers for the third season premiere of "Arrow," which aired Wednesday night.

The third season premiere of The CW's DC Comics-based "Arrow" was certainly a newsworthy one -- Roy (Colton Haynes) was in full red-hooded Arsenal mode, Diggle (David Ramsey) became a father, Lance (Paul Blackthorne) was promoted to captain and Oliver (Stephen Amell) and Felicity (Emily Bett Rickards) shared their first kiss.

That all sounds like good news, right? Well, for the most part it was, until Sara (Caity Lotz) -- also known as the Canary, the show's take on DC mainstay Black Canary -- was murdered at the very end of the episode by an unknown assailant, and discovered by her sister, Laurel (Katie Cassidy).

It's a lot to process, and CBR News participated in a press event last week at The CW headquarters in Burbank with "Arrow" executive producer and co-showrunner Marc Guggenheim, who dished on all of the above and more.

On when the decision was made to kill off Sara:

Marc Guggenheim: Basically, every season we spend what really should be our hiatus, and what really should be me relaxing on a beach, planning out the whole season. It's what we did in season one, it's what we did in season two, and we did the same process in season three. We just sort of started off talking about, what's the season about? I've spoken at length at this point that it's about identity; and we talked about what Oliver's journey for the year is going to be, and we talked about what all the other character's journeys were going to be.

Just in the course of those story conversations, we had this notion of starting the year off in a way that we typically end the year. It was just part and parcel with our plan for the year, ever since we started; the first ideas we kicked around.

Every time we kill off a character on the show, it's always incredibly hard. We're not "Game of Thrones," we're not "Sons of Anarchy." It's really, really difficult. We're very lucky, and I really meant this: Our cast and our guest cast are always wonderful people. We've been very lucky. When we were meeting with Brandon Routh -- part of our process with casting recurring characters is, we don't obviously screen people for their personality, but we have this great group, and a wonderfully welcoming cast. And Caity Lotz completely fit into that family. So it's always really hard to kill off someone who you just really enjoy working with, and you really love writing for, and love seeing on screen.

But as with Tommy's death, as with Moria's death, the story implications for this development are so far-reaching for the show, and affect all of the characters. We always call it "the terrible story math." It kicks off, obviously, a mystery that will drive us for at least the first half of the year. It will set Laurel on a trajectory that she's never had before on the show. It will create all these other complications and dynamics that I can't talk about, because it would spoil stuff. It buys us a lot of story, and it speaks to all the things that we wanted to do this year in terms of Laurel's character, in terms of Oliver's character, in terms of Felicity's character. It's always a hard thing to do, but it's really the engine that's driving the whole third season.

Will Lotz still appear in three episodes this season, as had been reported previously?

I wasn't lying! It's totally true. You're going to see her in the next episode, and then you're going to see her in at least a third episode.

We have stories that involve Caity Lotz, and one of the beautiful parts of the show is, we do flashbacks. We still want to tell the story of what happened when Sara washed up on the shores of Lian Yu after the sinking of the Amazo, and how she met Nyssa, and how she joined the League of Assassins. There's still a lot of story left to be told with Sara. But we did make a contract with Caity for three episodes -- I wasn't lying! You certainly haven't seen the last of her.

What type of impact does Sara's death have on Laurel and Oliver's relationship?

I think Sara's death probably pulls them closer together than further apart. That's not to say there aren't some significant moments of conflict between them, also. That's one of the reasons why we killed Sara off: the amount of story and richness that we get out of it.

And about that first kiss between Felicity and Oliver, and their subsequent decision to not pursue a further romantic relationship:

I'm very happy with the circumstance under which they have their first kiss.

Oliver and Felicity have a very emotional scene together in episode 2. This is not the last time we'll hear the words "I love you" in connection with Oliver and Felicity.

Guggenheim told CBR his thoughts on what Brandon Routh as Ray Palmer brings to the show that separates him from the rest of the cast:

We were thinking, who's the kind of character we haven't seen on the show? One thing that we haven't seen is someone who can play at Felicity's level in terms of the banter. Felicity, we always say, we write her as if she came in from a different show. But the problem is, she doesn't have anyone else to talk to like that. Low and behold, here's Ray Palmer.

Is there a chance Ray Palmer will be seen shrinking -- like his DC Comics counterpart, the Atom -- on Arrow?

I think anything is possible. My instinct is that if Ray Palmer's going to shrink, he'll probably shrink on another show. With "The Flash" in existence, there's no real compelling reason for us to do superpowers on "Arrow," because we can bring characters to "Flash" to have superpowers. We have plans for Ray that don't involve shrinking. But our plans for Ray are actually really cool.

On what Roy Harper's future looks like as a full-fledged costume vigilante:

That's a big component of this season. One of the things I felt we dropped the ball a little bit [in season two] was, we made a big deal about Roy joining the team, and didn't get a chance to do that much with him, because we were pushing a lot of other story. One of the fun things about season three is we really get to play with that, and you really feel like Roy is part of Team Arrow -- and it's more than wearing a costume. The trio becomes a quartet. That's definitely true in episode six. Episode six is a very Roy-centric episode.

Does the scene between Oliver and new father Diggle mean that Dig is off the team?

It did mean that he's off the team. But the circumstances of Sara's death change up a lot of things for our characters.

Guggenheim on that new Count Vertigo, played by veteran character actor Peter Stormare:

Certainly the idea of titles being different from people is part of the theme of identity of this year. I think you'll probably see that play out, not necessarily with respect to Vertigo.

I personally would love to see Peter Stormare back on the show. I don't think we've completely written out his character yet.

Oh, and what's up with Thea?

That question will get answered in episode two. You'll find out where Thea went at the end of season two, and you'll also find out what exactly was said in that limousine.

Looking towards next week's episode, titled "Sara":

["Sara"] is probably our most emotionally gut-wrenching episode -- as it needs to be, as it should be, because this character's death affects all of the characters on the show. It's kind of brutal. I don't want to spoil it too much, but we chose the title "Sara" because it actually has a double-meaning, and I really don't want to say more than that.

It's harsh. There's the question of what should be done with Sara's body. There's the question of, "Who do they tell?" Do they tell Lance, for example, that his daughter died a second time? There's the emotional repercussions for everybody, but it definitely has repercussions for Oliver and Felicity, and it has repercussions for Felicity and Ray Palmer. And obviously for Laurel. Laurel is very much at the center of that episode. We're also going to turn to a suspect in the killing. With us, you never know how things will get resolved.

I have to say, I think it's one of our best episodes. I'm really, really happy with it, because everything's sort of laid bare. It's all out there. Everyone's raw and naked. It was a really hard episode for the cast to shoot, particularly Emily, Stephen and Katie -- and Caity Lotz, who basically has to lie on a slab and not breathe, and actually does a very, very compelling job of being dead. It's really powerful stuff. It's a hard episode to watch. If you're prone to tears, or capable of crying during watching a TV show, you'll probably be crying.

"Arrow" airs 8 p.m. Wednesdays on The CW.