Just call Tom Cavanagh the man of one million faces on The Flash.

In last week’s episode, the CW’s hit superhero series decided to introduce yet another version of Harrison Wells when Earth-2’s version decided that he needed to get back home to his world with his daughter Jesse (Violett Beane). Earth-2 Harry knew that his friends at Earth-1 STAR Labs needed a strong adult scientist presence to steer them all in the right direction in his absence, so he and Cisco (Carlos Valdes) sent a combination IQ test/riddle/math problem to all the other Harrison Wellses in the multiverse to see if any of the other dopplegängers would be willing and able to take on the Earth-1 Harrison Wells role for a while. After many false starts, Earth-19’s version proved himself to be a worthy participant in this new experiment, so he came through a breach and made Earth-1’s STAR Labs his new home for the time being.

But just who is this new version who calls himself H. R.? Can he be trusted?

“He’s fun. A lot of fun,” Cavanagh teases to Nerdist on The Flash set in Vancouver. “I think what I could do is say that this show works best with conflict large and small, so I’m happy to drop off these little firebombs here and there… It’s one more fire that they have to put out. Is it best to extinguish it completely or to keep the embers burning, if you will?”

According to Cavanagh, this new version of Wells, along with the other versions seen through holograms in last week’s episode, were all of his own creation.

“Yeah, that’s all me,” he says. “Last year I was trying to fill in the gaps of what we don’t have on a daily basis on our show. We had a big bad but not a daily antagonist. Everybody is so winning on our show. They’re so great. Barry’s [Grant Gustin] great, Iris [Candice Patton] is great, Caitlin’s [Danielle Panabaker] great, Cisco is great. And I thought it would be great if there was a guy who wasn’t great, and that’s what I was last year. I was a daily antagonist, someone you couldn’t trust. A malcontent. A bit of a b****. Socially inept. But ultimately, he was kind of a good guy.”

He continues, “In the first season, he seems good but he’s bad. In the second season, he seems bad but he’s good. And in this season, well, I wonder what he is. A bit of a con man? But I thought… there are gaps that we have on our show, and I’m going to fill in that gap and do it sort of in the same way, be a part of something that is not a circle that we have on our show. But I didn’t want to repeat myself from last year so what I thought I would try this year is a guy who fills it up with comedy, if you will. The same element [regarding] if you can trust him or not is there, but in a different way. It’s kind of a variation on a theme… where are the gaps and where can I plug in some colors that we don’t have on our show without repeating myself or the other four Harrison Wellses that I’ve done?”

As for the other versions of Harrison Wells seen through holograms in last week’s episode, Cavanagh reveals that filming all those characters was a highlight, even if ultimately only a small fraction of the footage was used on the show. “They could have released an entire episode with those four characters,” he says with a laugh. “The reward for tolerance goes to Danielle Panabaker and Carlos Valdes for sitting through that, because they would just run the camera and I would just go. There’s a lot of stuff that we couldn’t use, like the French mime. It was essentially a shameless day of performing that we cut down to the stuff that we could use and still tell a story about the Flash.”

Cavanagh is grateful to The Flash showrunner Greg Berlanti for giving him so much freedom when it came to creating all the different versions of his character.

“Greg is extremely trusting,” Cavanagh says. “Partially it’s because we’ve worked together for a decade plus, so to let a guy go, ‘I’m going to do what I want to do,’ and to let him go ahead and do it and be comedic with it, as a general rule, you want to vet the artist before letting the artist paint the canvas in your house. You want to actually contribute and have this element—and in this instance it’s a comedic element—you want to make sure that it isn’t disruptive to the story, but it actually aids and abets it.”

He continues, “I’ve always felt like in the original Iron Man… even if you go back to Star Wars, in times of greatest crisis there was moments of comedy in Chewy and Han. Wherever you went to look, they hadn’t forgotten that making the audience laugh was the quickest way to bring them to your side. That’s what’s occurring here. Basically they wrote the roughest schematic and then I went to town.”

What do you think is up with this new version of Wells? What is H. R. hiding? Can the rest of the STAR Labs team trust him? Let us know in the comments section below or tweet me your thoughts at @SydneyBucksbaum!

The Flash airs Tuesdays at 8 p.m. on The CW.

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Images: The CW