A new season of The Flash is coming and, with it, there may be an all-new Harrison Wells. Over the course of the series, each season has introduced a new version of the character: the original Wells whose identity was stolen by Reverse Flash in Season 1, Harry Wells of Earth-2 in Season 2 and Earth-19's writerly HR in Season 3. At Comic-Con International in San Diego, Wells actor Tom Cavanagh teased his role in Season 4, explained what it's like to play multiple characters on the show and more.

Asked who he was playing this season, Cavanagh said, "Well, here's what's nice: so, my starting point is always the Reverse Flash. Correct? And so the Flash needs an antagonist, and -- on Superman -- you're always going to find a way to get to Lex Luthor, and so we're sort of in that same situation, where I'm the Reverse Flash, he's the Flash and there's going to be a way to get to Reverse Flash but you can't do that every season or every episode, right? So, in the meantime, we've got this one guy, Wells, and then from that Earth, that guy Wells, and then that guy Wells and that guy Wells and that guy Wells -- there's lots of Wells!"

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The Flash HR Wells

"There's a line in the movie Rocky, 'You got gaps, I got gaps, together we fill gaps!'" he continued. "Cisco's so winning, Caitlin's so winning, Barry is so winning, Joe is so winning, they're all so winning and so, in Season 2, it was like, 'Maybe if we had a jackass who has no social skills and is abrasive' and then that was Harry. And then in Season 3, we had a lot of darker storylines, so like, 'Maybe we add a little more humor' and that was HR. And so this year, we've had a different villain and so I think there's going to be areas that we could use a different Wells. We're going to start with Harry and then find a way, I think, to try and get a different version of Wells in there, be it some version of Harry or whatnot as the season's gaps present themselves."

Though he suggested there could be "a different version of Wells" this season, he couldn't offer many more details than that. "I mean, there is stuff that's involved with this season that we're talking about how Wells might become a different version of Wells, but I think that's a storyline too far from me to give up, but you'll see it!" he shared.

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Cavanagh's castmates are similarly in the dark. "Dude, I have no idea. I have no idea. I have no idea what Tom [Cavanagh] is going to do this season," Carlos Valdes, who plays Cisco "Vibe" Ramon, responded when asked about his character's relationship with Wells this season. "Sort of answering your question a little bit... I know that he's supposed to be Harry at a certain point in our season."

HR Wells

"I don't know which version of Wells we're getting, so it depends. If it's Harry, Joe's going to be mad," Joe West actor Jesse L. Martin said with a laugh. "If it's HR, I liked HR! I respected him. I still didn't trust him, but I respected him. So I don't know which one is coming. I'm sure I'll have a reaction to whoever it is."

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Cavanagh also explored the idea of whether the original Harrison Wells, who was killed by Reverse Flash years before the events of Season 1, could return to the show in some capacity. "When considering not just this season, but it looks like The Flash I heard contractually is going to run for the next 27 years... There's room to like see what you can do with it, and that seems like an obvious one, but then I think it paints the writers into a corner a little bit, because -- first off -- he's dead. He dead!" he explained.

"The best part of that story… we've sort of told, and there is a bit of a timeline where it doesn't necessarily fit all the other," he added. "You know, there's a lot of machinations, a lot of Tumblrs, and it's like, say, 'We've got Vibe, we've got progression with Caitlin, we've got all this kind of stuff' and that does take on, in their stories, a little bit of a timeline... You're like, 'It's definitely got to be on the table! We've introduced Tess, we've introduced Harrison' and so I think the writers are like, 'Yeah, we have that, that's over here, on this 3x5" writing card and we're not quite sure when we'll introduce it' but yeah."

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"For me, the thing I like the most, the writers and producers have created this organic reasoning behind 'that person comes from this Earth and this Earth' and it makes sense, you know? Nobody would be shocked if a portal opened and Wells came through and he was like, 'Well, how are you? It's nice to see you. It's been a long time.' And everyone's like, 'Uh, we've never met.' 'Hah! That's what you think!' Right? I just wrote one scene! And it's nice to be able to do that and then make sense," he concluded.

Harrison Wells

He went on to describe his different roles within the series as "a joy," saying, "You know, there's only a small number of actors that can really check the superhero suit box. I feel like it's a real privilege at my age to be like, 'What? I get to put on a suit?' And then another thing was the idea that you're two people in the same scene! It's Shakespearean! Theater is rife with examples of you're talking to you, or Viola is so-and-so! You know what I mean? And so to have that opportunity, where they have the bells and whistles that have figured it out and you get to do it… This is self-serving, but the idea that HR thought Harry was unbelievably cool, and Harry thought HR was an idiot, and to have those two guys like, 'You're awesome!' and 'Shut up.' That dynamic? I just love that dynamic! And so those were, for me, some of the most joyous moments of the four years of doing The Flash."

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Valdes feels the same way. "Oh, it's been a blast. Tom is like such a great actor to work with. He's always on, and his neurons are always firing a mile a minute. But it's good! It has this weird effect on set, where everybody absorbs it through osmosis and all of a sudden everybody's perked up and everybody's moving and thinking quickly and thinking on their feet and allowing it to breathe in the moment, and that is a fundamental asset, I think, to the way we work, so it's been hugely fruitful for me," he shared, adding, "He's very good at physically characterizing his roles, so it's very helpful."

Starring Grant Gustin as the Scarlet Speedster, The Flash returns Tuesday, October 10 at 8 p.m. ET/PT on The CW. The series also stars Jesse L. Martin, Tom Cavanagh, Carlos Valdes, Candice Patton, Danielle Panabaker, Keiynan Lonsdale and more.