Liam McIntyre on Tonight's Midseason Finale of The Flash

Tonight on The Flash, The Weather Wizard (Liam McIntyre) will return, teaming with Captain Cold, the Rogue who broke him out of jail last season. And they're here to make things really hard on Barry Allen and company, just as he's already got some stuff going on with his adoptive family.

Star Wars: The Force Awakens star Mark Hamill is home for the holidays, too, back in a role he first defined more than twenty years ago. Of course, we mean the role of James Jesse, The Trickster, on The Flash.

The trio is brought together by Weather Wizard, who wants to take out The Flash, and seems to think these other Rogues have a skillset and maybe a little knowledge that can help him.

McIntyre joined ComicBook.com to discuss the episode.

DC has a long history of legacy heroes and villains, and you're one of the first characters to take up a mantle. Has it been interesting to kind of watch the world evolve around you to where that's pretty common?

It is, and it's pretty interesting what they were able to do with the brothers, too. Instead of going with the more classic story of Mark killing his brother to take his wand and become the Weather Wizard using his power, they just went the metahuman route where they've got the powers already.

I also got to be one of the first metahumans who got to show himself to the regular world. He just stormed into the police station and wrecked up the place and it's the first time they realized it was really serious.

The Weather Wizard is one of the most exciting characters because he's truly powerful, too, which is sort of wonderful. And it's nice to know that what we did with our stuff worked, and now it's worked consistently between all the shows. It's nice to be a tiny little piece of the DC jigsaw, as it were.

This time around you're getting to work with Wentworth and with Mark Hamill. Did you talk to Mark about the fact taht this is essentially the fulfillment of a promise from 25 years ago, when Hamill was meant to lead the Rogues in a Season Two premiere that never happened?

Kind of wonderful, isn't it? I had a chance to talk quite a lot with Mark, and he's a wonderful man. He went a lot into his original Trickster and how had had talked to Greg Berlanti and Andrew Kreisberg about what the Trickster would be doing in this universe or in this version of The Flash. I think in the original version of what they were looking to do with the Rogues, he was going to be working with Mirror Master, if I'm not mistaken, and it was going to be a proper Rogues Gallery of sorts.

You know, what I didn't know about Mark Hamill and probably should have, is that he's brilliant at comics. He gets comics more than almost anyone I know, so he was a walking encyclopedia of that stuff. I think the first thing we talked about after we finished our first scene was "So! Your character, my character, Wentworth's character, this is how we all go, this is where we come from, this is what we represent." He was into it; it was wonderful!

I think Mark found it kind of wonderful that he got to live in that world and fulfill that, and being such a comic book aficionado, I asked him about that: it might have been kind of amazing and then kind of sad when it didn't work out the first time the way it should have.

I don't want to speak for him, but I think this is for him especially a chance to live out that thing that was going to happen so long ago, and for us all to be part of that.

With your character, I feel like the decision to make him act as an agent of vengeance on his brother's behalf rather than killing his brother gives him an edge of humanity...

Yeah, thank you. I think the first thing when I first got the character...one of the things I learned from Spartacus and the writers and the way the performers performed the villain characters was, the best part about them is you kind of wanted to root for them sometimes. You kind of got where they were coming from, and I always think that the best villains aren't the ones you can just dislike straight out of the gate.

You know, when you're trying to kill the lead character most of the time, it's not as easy to be not-disliked. But if he's coming from a place where, yeah, he's a criminal but there's certain reasons and he's doing things in a certain way...! And things have happened to his family, which he attributes to first Joe and then later to The Flash. It gives him a much more rich way of approaching the world, where if he's this horrible psychopath who killed his brother, there's not so many places to go.

Is it safe to assume that the relationship your character has with Barry is going to change with this episode?

It especially changes our relationship because what's important to remember is that in the timeline they're operating in, all he knows is that The Flash turned up and thwarted his plans to get revenge on Joe, so The Flash has kind of become an enemy number one for Mark, where previously that had been Joe.

To me, the most exciting part about this episode is, it's very much the beginning of the Rogues in a lot of ways. You get to see the relationship of Snart and Mardon and how they interact together and that potential power play that would be afoot there where Snart is clearly a criminal mastermind but Mardon fancies himself as one, extremely powerful, moreso than any other character, and two, quite smart in his own right.

And then the wild card that is James Jesse and the Joker-esque quality of him, if you will, where you just don't know what you're going ot get form minute to minute, which is so exciting to watch as an actor.

Right up to the very last second, it's going to be exciting for fans and there's going to be a bunch of stuff that shifts a few things. It'll be great.

I would think that a lot of the time, playing "the muscle," the guy who's more powerful than necessarily being the mastermind, can be dull -- but this antagonism, where you're maybe a swing vote between two guys who feel like they're the smartest guy in the room, has to be interesting.

That's why I say it's the most exciting for me. Here's Mark, who's really pushing -- he's on the front foot here. As we all know, Snart has his kind of double agenda, which Mark isn't really aware of where Snart is in cahoots with Barry a little bit but he's also out for himself so you never know which way he's going to fall. It's exciting to be like "Okay, you guys, this is how we're going to do it," and then realize that Mark isn't going to get what he wants all the time.

It's interesting to see him as not really the swing vote, but he comes in wanting to be the boss. And as you know with the Rogues, that's easier said than done.