Last Wednesday on The CW's freshman drama "Arrow" -based on DC Comics "Green Arrow" - actor Stephen Amell's Oliver Queen encountered a would be mentor/assassin named Slade Wilson during flashbacks to Ollie's years on an uncharted island. The problem for comic fans is that Slade Wilson -played by actor Manu Bennet -is the alter ego of arch villain Deathstroke, whose split-masked likeness has been stalking the series flashbacks without a word for months.

The twist leads to tonight's new episode "The Odyssey" where Wilson and Queen will team up to attempt an escape of the island while in the present, things progress with modern Ollie's continued quest for justice as Starling City's hooded vigilante. And while the question of both a Slade Wilson and a Deathstroke is explored on screen, DC will release it's latest digital comics chapter of "Arrow," revealing the mercenary's origin.

For some history and some clues on the future of their version of Deathstroke, CBR News spoke with "Arrow" executive producer and show runner Marc Guggenheim. Below, the writer explains how they took the DCU heavyweight from comics to screen, why the tone and arc of "Arrow" necessitated a change in Slade's origins and what the show's second season pick up portents for the season finale all while showing off an exclusive look at the Deathstroke costume design.

"Arrow's" Deathstroke and Slade Wilson as imagine by costume designer Maya Mani and illustrator Andy Poon.

CBR News: Marc, I've got to say that since I have to follow the ins and outs of "Arrow" for this job, I usually am up on the casting news surrounding any episode. But I hadn't seen a photo of Manu Bennett yet, and so when the reveal hit in last week's episode, it caught me by surprise that he was supposed to be Slade even though we'd already met Deathstroke.

Marc Guggenheim: That's great. The thing about that was that we originally wanted to keep his identity a secret. In fact, when we were filming we sent out script pages and called the character something different than "Wilson" so we could really keep it a secret. But then once we cast Manu, we had to put out a press release and that, and it became much harder to keep it a surprise. I'm glad to hear it still played in the body of the episode. That's nice to hear.

How did you light upon using Deathstroke to begin with? The character seems a good fit for this version of Green Arrow, but he's not necessarily a GA villain. When did you decide to work him into the proceedings?

Honestly, it all goes back to Geoff Johns. You're right. Deathstroke is not synonymous with Green Arrow, but during the scripting of the pilot, Geoff suggested, "Wouldn't it be cool if when we're on the island as we begin, we see some artifact that ties into the comic? What if it was Deathstroke's mask?" And Andrew [Kreisberg] and I just said, "Done." It was a no brainer. So it was Geoff's idea, and then that mask caught a lot of people's attention. We made the decision to bring Deathstroke in during episode five. I think that we weren't quite sure how successful the character would be. I've got to give a lot of credit to our costume designer Maya Mani. She went through design after design to really get the look right. Especially on a TV budget and a TV schedule, that is a hard costume to get right.

And when he appears in episode five, we felt that not only did Deathstroke work, but it was also our biggest island episode to date. That really had us thinking more in terms of story for him, and Twitter would light up whenever Deathstroke would show up on screen. Our plan from jump was that the guy beneath the mask was not Slade Wilson. We always knew that we'd introduce Slade Wilson later in the body of the series. And as with most things "Arrow," we ended up doing that sooner than we expected. So then we went through the casting process and saw like a bajillion actors for the role. Manu was so strong that we really had to make a choice. Do we pick someone with a heavy New Zealand accent knowing that Slade Wilson was American in the comics, or do we just go with the best actor for the role? We went with the best actor for the role, and his performance has just grown by leaps and bounds with each new episode. He's really terrific in Wednesday night's episode, and he's a real high point in episode 15, which is the most recent episode we've completed. You'll be seeing a lot more of him. He's a lot of fun to have on the show and a lot of fun to write for.

Since you knew you wanted to split Deathstroke and Slade at this point in your story, what were the things you felt you absolutely had to have as part of the character from the comics?

I think with respect to Deathstroke, getting the look of the costume right was very important to us. Losing the buccaneer boots and some of the gaudier aspects of the costume helped keep it in line with our grounded approach. But at the same time, we worked on maintaining the lines and the iconography of the original George Perez design. In fact, if you look carefully at the Deathstroke costume -and I know that's hard because he's always in motion -he's wearing a kind of kevlar element where the lines of it actually match the lines of the comic book costume. So there were some very subtle ways that we wanted to keep the character true to the look established way back in "New Teen Titans" #2.

And with respect to Slade, we realized that even if he's not American...well, you'll definitely want to tune in on Wednesday because there are a lot of little Easter Eggs for the fans who are familiar with Slade's backstory. I don't want to spoil too much of it, but in making Slade someone who is a military guy and giving him a family history that is familiar to the comic fans, it all helps the character be true to his roots.

And the swords don't hurt either, I bet.

No. And the swords were actually a very big piece of it. You'll want to see that in episode 14 on Wednesday. I don't think I'm spoiling anything to say that we've been working up to a confrontation between Deathstroke and Slade Wilson, and the question becomes how and when will that happen. I think it'll be a fun moment for fans.

This is also the first week Deathstroke shows up in the comic tie-in online. At the start of the show, you were obviously just writing scripts for TV, but at this point are you breaking ideas for comic tie-ins as you work on episodes in the writer's room?

To the extent we can. Obviously, we have to work around artist's schedules, but I will say that now that we know we're doing the digital comic, for example, I wrote a chapter that Mike Grell is drawing right now that introduces a character who later appears in the television series. That's all very intentional. We're able to make the two speak to each other very closely. That's a lot of fun. You only have 42 minutes to tell the story, and so a lot of stuff ends up on the editing room floor. You just don't have the chance to explain a lot of the stuff you want to explain. Comics are really helpful for that. We're able to add in a lot. The chapter Mike is working on right now is called "The Pieces Missing," and it's just full of little moments in the story of Oliver and Diggle over the first six episodes that we didn't get a chance to do on the phone but I thought were really important. For example, in the pilot Oliver knocks Diggle out with a choke hold. We always wanted to have Diggle call him on it in episode two, but we tried to do so many other things there that we didn't get a chance to film it. So I got to put that scene in the digital comic. It's extra material for fans of the show. And also with comic books, even with the chapters that don't tie directly into the show's episodes, we try to tell stories that take advantage of comics unlimited budget.

See CBR's excusive preview of this week's "Arrow" digital comic.

In this week's installment of the comic, you're playing more directly into the episode, right?

It's actually the perfect digital chapter because it shows how strongly we're tying the comic in with the TV show. In this week's episode, you'll hear this whole back story that Slade tells about how he got on the island, and the comic book actually dramatizes it. If you want, you can read it before the show airs and get a chance to visualize it, or you can read after the show and see it tie in the comic pretty strongly.

Lastly, I probably should have mentioned this at the top of the call, but it's very new news...congratulations on a second season pickup!

Thank you! We're really, really excited. We just got the news shortly before it broke on the internet, and so we're still reacting. We kind of expected a second season, and we were planning on one, but I've got to say that the timing really took us by surprise pleasantly so.

We've been watching two stories all season between the modern day battles against Merlyn in Starling City and Ollie's time on the island. I assume those two ends are going to connect at some point. How does having a definite Season 2 on the horizon impact how you'll craft those stories through the finale this year?

Quite frankly, it doesn't change our plans for the end of the season since, like I said, we were planning things with a second season in mind. It really doesn't alter our plans one iota because we've always planned in Season 1 to build to two big moments -one in the present day and one in the flashback. We don't necessarily build a question between what's happening on the island and what's up with Merlyn in the present day, and we actually dismissed that as an option early on in the season in the writer's room because we felt like that'd be too much of a coincidence. The connection between the present day and the flashbacks will stay, like we've been doing, thematic in nature. But hopefully these two big moments we're building to will resonate with each other because that's how they're designed.

"Arrow's" "The Odyseey" episode debuts tonight at 8:00 Eastern and Pacific on The CW.