Warner Bros. Animation's second half of its cinematic adaptation of Batman: The Long Halloween closes out Jeph Loeb and Tim Sale's classic Batman story. As the Dark Knight scours Gotham City for a serial killer striking on a different holiday each month, the city's District Attorney Harvey Dent finds himself descending into madness. The pressures of Harvey's job collide with his mental illness and tragically leads to his transformation into the iconic villain Two-Face. Both sides of Harvey's persona are voiced by Josh Duhamel.

In an exclusive interview with CBR, Duhamel revealed how he connected Two-Face's origin story to his portrayal of pre-transformation Harvey Dent. He also discussed how he approached leaning harder into the sinister potential behind the DC character.

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Batman and Harvey Dent, Coin - The Long Halloween

There's so much menace in it, where did you find the voice for Two-Face?

Josh Duhamel: It was something [voice director] Wes Gleason and I worked on when I got in there. We wanted to do something that felt real, how what happened to him would actually affect the way he speaks, trying to find it from a realistic point-of-view but also there was something bubbling up even before he became Two-Face, you could see him start to crack. I don't think they are two different characters, Harvey is the same guy, but that dark side that he kept at bay has come to the forefront and that was only escalated by the fact that he was literally deformed and the comprehensive damage done to his vocal cords. That's something we also tried to do, we tried to find a voice that was not what I had done before but kind of in the same family but different and kind of menacing.

With Harvey's psyche descending steadily over the course of the story, was this something you recorded in sequence or did you have to keep in mind where he was mentally and jump around the timeline?

No, we recorded it pretty chronologically. Luckily on these, you kind of start at the beginning and go all the way through the script, unlike a movie where you shoot completely out-of-order. We got a chance to figure it out as we went how he was always cracking and where these moments are and see that this guy is not well. That was fun, it was a different, more involved version of Harvey that comes forward in the story.

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One of the most effective scenes in the movie is Harvey literally arguing with himself in a courtroom. How was it finding the performance of Harvey at war with himself in front of all those people?

Yeah, this is a guy who was dealing with his dark side for a while and I think it was a culmination of two things: His pressure at work and trouble at home and just the mental instability that is present with this guy. He's definitely battling a duality of personalities and then it became front and center as soon as he had that acid thrown on him in the courtroom. That was fun and a challenging couple of days of work going in there and finding that character and how he could go from one extreme to the other.

The last time we spoke, you were saying that you've known Wes Gleason for a long time and worked with him before. With you going into some really dark areas in Part 2, how was it working with him to find that space creatively to go for broke with your performance?

That dude is so good at his job, it's crazy. He's so supportive, him and [director] Chris Palmer and the whole team over there, from the animators to the audio side of it. For me, I don't work with any of the animators so I don't know what it's going to look like but I could tell they were taking a lot of care in making sure there was a real evolution about how he goes from regular Harvey into full-on Two-Face and that it wasn't just a snap moment that happened. It was something that was bubbling up and you can kind of see him start to crack. It really came to the forefront in that courtroom scene.

Because I have guys like Wes and Chris there to measure that, it's a totally different art form doing this kind of stuff. For me, it's a great exercise in acting because you're depending solely on your voice and, when you're an actor on camera, I've realized the last several years how important your voice is. I've worked a lot with [filmmaker] Larry Moss over the years and Larry focuses on that as much as he does your acting and it's so true. It's as much about your voice as your performance on camera so this kind of stuff actually helps me on camera as well and I love doing it.

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In the comics, The Long Halloween had a direct sequel in Dark Victory. Are you open to reprising your role as Two-Face and push your performance into new directions, even more into his dark side?

Sure, I'd love to do it! I've done several things with these guys over the years and hopefully, they'll have me back. With this half of the movie, my girlfriend and I watched it last night and I just thought they knocked it out of the park with the tone and that they captured something dark and looming. They weren't afraid to leave it quiet at times and that silence is deafening. It takes a lot of courage for any filmmaker to allow these moments to breathe because so many times it can feel like you have to fill every second with something and they trusted that those silences are as powerful as the sound design they put in there. Between the sound, the tone, and the retro sort of animated look they have, I just loved it.

Batman: The Long Halloween, Part Two arrives digitally on July 27 and on Blu-ray Aug. 10.

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