There is perhaps nothing deadlier than a living, walking, nuclear time bomb.

And that's pretty much exactly what Ronnie Raymond was in last week's "Flash" episode, "The Nuclear Man." After a brief confrontation with Barry Allen, the Firestorm matrix crackling inside of Ronnie became unstable enough that, if left unchecked, was set to go critical and wipe out Central City. To save the city, Ronnie's body, which was controlled by Martin Stein, left for a secluded area where they could kill themselves without taking innocents along with them. At the last minute, Barry and Caitlin Snow arrived with a device that could solve their problem, but the gadget malfunctioned and the episode concluded with Ronnie apparently going nuclear and exploding. It's the end of Ronnie and Firestorm, or, so it seems.

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Ahead of tonight's episode, "Fallout," Robbie Amell spoke with CBR News about presenting a unified Firestorm as he and Stein learn to co-exist. We discuss the fledgling hero's current power levels, why his on-screen outfit is a better choice for the character than the colorful comic book costume, the possible transformation of Caitlin, Ronnie's fiancee, into classic Firestorm arch-nemesis Killer Frost, and why he's happy to be returning to comedy for his big screen release, "The DUFF."

CBR News: Did your previous TV series, "The Tomorrow People," prepare you at all for the role of Firestorm?

Robbie Amell: There are a lot of similarities, physically. Flying is kind of similar to teleporting -- you're jumping into it, or jumping out of it, and then running off screen. The TK blast is pretty similar to the Firestorm energy fire blast. Physically, it was everything I had been doing on "The Tomorrow People." The nice thing is, it was much of the same crew and the same visual effects department. I knew I was in good hands.

The comic book version of Firestorm also has the power to alter the molecular structure of pretty much anything. What is "The Flash" counterpart capable of?

At this point, flying and nuclear blasts. We haven't really taken a shot at the molecular transformation, but I feel we'll get there at some point. At the end of the next episode, "Fallout," you find out that Martin Stein (Victor Garber) and I have decided to try to hone our abilities. We do think it's important to become Firestorm when needed, that we use our powers for good. That is something we can explore in future episodes.

That power may be a future addition, but Firestorm does get to fly. Some actors find the wirework required to pull that off tedious, if not painful. How was the experience for you?

It's the coolest. You get to fly! I'm not going to complain about wearing a harness every once in a while, or when Grant and I are flying through the air. He posted a picture of us on his Instagram -- It's the two of us sitting on bicycle seats surrounded by green screen. It's really fun. The harness isn't comfortable, but at the same time, I just can't believe people complain about it. You have to think about what the final product is going to look like. Getting to see yourself fly, there's nothing cooler. It's what I dreamed about as a kid.

The original Firestorm incarnation featured Ronnie in control of the body, and Martin as a voice in his head. What are the rules this time around?

That's what we get into next episode. So far, you've only seen this out-of-control, schizophrenic version of the character, except towards the end of "The Nuclear Man." That was when they were hopped up on drugs and Martin was able to take control of my body.

In the next episode, "Fallout," you get to see the aftermath of what happens when they separate. There are not only the two of them to consider, but their significant others. Ronnie hasn't been with Caitlin (Danielle Panabaker) for over a year, and things have changed for her. She's now hunting metahumans. She's in a different place. Ronnie lost a year of his life because of S.T.A.R. Labs, and may want to be somewhere else, or try something new. Martin and Ronnie quickly realize, maybe it's better to figure out how to balance the power. At the end of the episode, you really get a taste of what an in-control Firestorm could be.

How would you describe the dynamic between Ronnie and Martin once they split?

They are totally sick of each other. They fought for control of the body and they were inside one mind for so long that they want nothing to do with each other.

On the flip side, as you said, Caitlin and Ronnie have reunited. What obstacles do they face as a couple?

They are in different places than a year ago. They were planning their wedding and honeymoon. Then, this tragedy struck and she thought she lost him. Caitlin's life is just different. She isn't just a scientist any more. She's part of Team Flash and she has responsibilities. Ronnie may be looking for something a little quieter. The last year, he has been fighting for his life. There's definitely an uphill battle for the two of them, but there's still a lot of love there and they want to figure it out.

And then we have General Eiling (Clancy Brown), who is a man on a mission. What does he want?

That's kind of a catalyst for what brings Ronnie and Stein back together. Separate, they are two normal guys. Together, they are an unbelievably strong superhero. Eiling can get what he needs from one of them alone, so they are kind of helpless unless they fuse. The danger is, if they fuse, can they figure out how to separate? If they fuse, who is going to be in control? You finally get to see what a full-powered Firestorm looks like.

We've seen photos of you in a Firestorm outfit already. How does it compare to the traditional yellow and red costume?

Well, I definitely didn't want a red and yellow costume. It would be really had to pull off. Even the Flash costume is a much darker red than it is in the comics. The worry of the Firestorm costume is if it goes the Ronald McDonald route, especially with the puffy sleeves. Up to this point, the only thing that stays with the costume as I change is the splicer. The splicer is really the only significant piece of the costume. The rest is whatever Ronnie happens to be wearing when the splicer goes on. So, there is no costume, yet, but I'm sure Cisco has something in mind.

Now that Firestorm is part of the Flash universe, would you like any his foes to pop up? Killer Frost? Hyena? Black Bison?

They are definitely talking about Killer Frost, and I know Danielle is excited about that. It would be fun to turn your fiancee into your enemy. We could have a great time with that. I think that's a little ways down the road. There are a lot of big Flash villains introduced already. Like everything else, you need to work for it. You need to earn it. I am excited for Danielle, though. I think there's a tease coming in the next few episodes for Killer Frost.

Your "Tomorrow People" co-star Peyton List is also guest-starring as the Golden Glider on "The Flash." Did she call you about it, or was the casting a surprise to you?

It was a total surprise for me, but once I found out, I called her and we started chatting about it. The crew on Flash is eighty-percent from "The Tomorrow People," so it's kind of nice for both of us to work with old friends and people we spent a year of our lives with.

According to IMDB, your next episode is "All-Star Team Up." Where does Ronnie fit in for that?

I don't know who put that on there. My next episode is "Fallout," and then I'm not around for a little while. I won't be back until the end of the season.

Shifting gears, how does it feel returning to your comedy roots with "The DUFF?"

It's awesome. What really makes "The DUFF" special for me is, my very first project was "Cheaper by the Dozen 2." That's really the last time I had a wide release feature. It was my first job ever. To be back on the big screen in a wide-release movie almost 10 years later is really special to me.

With that being said, it's so incredible to be part of a project that has a chance to be one of those timeless classic teen comedies. A lot of people that have been seeing it have been comparing it to John Hughes movies, or "Mean Girls." It's all the ones you want to be compared to. It's really exciting. I hope people enjoy it as much as the people who have seen it.

Why do some actors feel comedy is the hardest genre to get right?

It's either black or white. It's either funny or it isn't. You can do drama and interpret it in a bunch of different ways. Comedy either works or it doesn't. There's a formula to it and it's just kind of scary. If it's not funny, you know it's not working. Whereas, in drama, just because one person isn't feeling it, that doesn't mean another person isn't. I think you have a wider range if you are doing a dramatic role. It's based more on the dialogue you are working with, and the hands you are in with the writers, the directors and producers.

Your "DUFF" character, Wesley, doesn't always come off as Mr. Congeniality. What drew you to the role?

When I first started reading it, I thought it was a little cliche and a little too stereotypical for the jock. I quickly realized, this guy isn't what he seems. He has a good heart. There's a little more charm to him. Everything is coming from a good place. He talks before he thinks, sometimes. In the beginning of the movie, I had to reach a little deeper and try to say these things as non-threatening and unassuming as possible. Then, I got to bring a little more of myself to the second half of the character. I had fun with it and tried to make Mae [Whitman] laugh.

Wesley tells Bianca (Whitman) she is a DUFF. What would you have been labeled in high school?

Everybody goes through their own time of feeling like a DUFF. I had bad skin in high school, so there were times I definitely felt like a DUFF. But I also played a lot of sports, so I could easily have been classified as a jock.

Was moving your pecs in that locker room scene scripted, or was it a special talent that you offered up?

No, that was an improvised experiment. I told the director, "I'm going to try something. If it comes across douchy, promise you won't put it in the movie." I didn't tell Mae I was going to do it, so that's her genuine reaction, laughing at me and thinking I'm an idiot, which was great.