At an early screening of AMC's "Preacher" pilot, series stars Dominic Cooper, Ruth Negga and showrunner Sam Catlin spoke with the press about the challenges -- and rewards -- of adapting Garth Ennis and Steve Dillon's acclaimed series. They also revealed some specifics from the source material that made it into the show and when fans should be on the look out for them.

At their most basic level, both the comic and the series follow the exploits of Jesse Custer, a small-town Texas preacher who struggles with his own checkered past and the eccentric residents of his hometown. Complicating matters, Custer is reunited with his ex-girlfriend Tulip (Negga) who also happens to be an assassin with a penchant for explosives. When the child of a demon and an angel named Genesis inhabits Custer, it grants the preacher great power -- though it comes at a price.

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Along with Catlin, Seth Rogen and Evan Goldberg adapted the comics for television. "They've been great collaborators. It's been really good that I've been the outsider to it and they've been the geeks to it," said Catlin, though he initially had some trepidations about working the famous pair. "You never know what you're getting into when you deal with celebrities, really powerful celebrities, because they have every opportunity to fuck you up. Seth and Evan are just the nicest, most down-to-earth people."

Catlin was not familiar with the comic prior to his work with Rogen and Goldberg, and when he began to prepare for the adaptation, even he didn't wasn't sure it could make the transition -- until he recognized the potential of the comic's universe. "On 'Breaking Bad,' the story starts, it's in Albuquerque, everyone recognizes it and everyone knows the rules. He [Walter White] has stage three cancer," Catlin said. "That's what's so exciting about 'Preacher.' From one moment to the next, you can go from here all the way over to there."

While the comic wanders across the globe from the start, "Preacher's" first season, according to Cooper, mainly takes place in a small Texas town. Custer will try, in vain, to save the difficult residents from their own shortcomings. If the show continues on to further seasons, it will likely span much of the globe, and possibly travel all the way to Heaven. Fans can also expect that the Saint of Killers, the assassin dispatched by Heaven to kill Custer, will come along at some point, as will the "Fuck Communism" lighter made so iconic by the comic, though it will not appear until next season.

"Maybe he hasn't given up on God from the beginning," Catlin said of the show's lead. "Maybe we see him actually as a preacher trying to be faithful -- he's still a hot mess. As long as you still have the drive of what Jesse wants and what he's looking for, you can go anywhere you want."

When preparing for the role, Cooper fixated on the necessity of Custer's darker side. "He's depressed. He's a drunk. He's regretful. He's trying to change, and by the end, pretty much given up. My worry was always being surrounded by these extraordinary, vibrant, colorful, amazing characters who have these dynamic wonderful scenes and they're fun and funny and there's just this morbid depressing, bloke in the middle." But, Cooper said, the character's "stillness" balances the show.

That balance disappears when Custer gains the powers of Genesis, allowing him to control people by speaking to them with "the voice of God." Custer will struggle with the unique gift throughout the show's first season. "It's him learning how to control it," Cooper explained. "He mistreats it, quite badly, and causes severe damage."

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Custer will also struggle in his relationship with Tulip and the vampire, Cassidy (Joseph Gilgun), a trio that forms a unique bond. "It's a brilliant, heartfelt love triangle between the three of them," said Cooper, despite the fact that each of them is extremely dangerous -- and perhaps none of them more so than Tulip.

Negga describes Tulip as a "DIY sort of assassin" who teaches herself the lethal arts. Gaining these skills took a little work for Negga as well. "I get very nervous about hitting people," she said. Nonetheless, she approached her fight choreography as dancing, learning the skills she needed to bring her character to life.

As eccentric as the series and its characters may sound, Catlin brought the story to its baseline. "We hope that people take the show at face value. It's just about a guy who's looking for answers and kicking ass along the way, he's got this girlfriend who's a sociopath and a best friend who's a vampire/drug addict. You know, it's a simple story," said Catlin.

"Preacher" airs on AMC this May.