Tim Blake Nelson on How He Approached 'Just Mercy' Differently Than 'Watchmen' (Exclusive)

For Tim Blake Nelson, not all acting jobs can be approached the same way. For the upcoming legal drama Just Mercy, the veteran character actor takes on the role of Ralph Myers, who, like most of the characters in the film, is based on a real person and plays a pivotal role in the landmark court case that the film portrays.

Nelson was on-hand to speak with PopCulture.com last month at the Just Mercy screening at the Austin Film Festival, and opened up about what went into becoming Myers, and how it differed from his Watchmen character of Looking Glass.

"Sometimes that task is more daunting than others," Nelson said. "This was a particularly challenging one — he's so extreme. The real fear I had was depicting him in a credible and honest way that really delivered that guy onto the screen. [Not] that people were gonna scratch their head and think, 'That's not a real human being up there.' Finding that balance was the particular chore in this one. Luckily I had a lot of time to let the character seep into me."

But Ralph Myers isn't the only extreme character Nelson's been playing these days. On HBO's Watchmen, the actor plays Looking Glass, a Tulsa police officer who wears a reflective mask and excels at suspect interrogation.

"That's a completely different process," Nelson explained. "I'm cross-referencing my own experience and trying to find what Damon Lindelof wants inside of me. That way I'm sourcing the character as honest and credible and human inside of this extreme alternate universe. That's a very different process than allowing an extravagant, but very real character in, and trying to put him on screen so that people can experience the real story behind it."

Nelson also said that while Lindelof's continuation of the landmark comic series from Alan Moore and Dave Gibbons is a high concept series, the "only CG is the mask itself."

Just Mercy stars Michael B. Jordan as real-life civil rights lawyer Bryan Stevenson and Jamie Foxx as Walter McMillian, who in 1988 was wrongfully accused and convicted of a murder he didn't commit. It's slated to open in theaters Christmas Day.

Nelson's Looking Glass featured prominently in the first several episodes of Watchmen, including his character's dark origin story in the recent episode, "Little Fear of Lightning." However, after a cliffhanger ending, it's still unclear exactly what became of his character, though last Sunday's episode, "An Almost Religous Awe," teased that he survived an unexpected visit from the Seventh Kavalry. While he may be alive, his whereabouts — and how he may play into the show's finale — aren't yet clear.

New episodes of Watchmen air Sundays on HBO at 9 p.m. ET.