It isn't the fall TV season until a believer and a skeptic start investigating supernatural occurrences. Fans looking for a classic Mulder-and-Scully story will find it in Evil, a new drama from The Good Wife creators Robert and Michelle King, but beneath that framework lurks a genuinely unsettling energy that keeps the show feeling unpredictable. Evil, premiering Sept. 26 on CBS, is one of the year's best new broadcast shows: a slick, creepy series that comes out of the gate ready to challenge what a network procedural can do.

"I was totally surprised by the tone of the pilot," star Mike Colter told TV Guide at the Television Critics Association summer press tour. "When I read the script, it didn't seem like a Kings script, and I'd worked with them before. But that's the great thing about it."

Colter plays David Acosta, a priest-in-training who works for the Catholic Church exploring claims of possession and demonic activity. David is intrigued by psychologist Kristen Bouchard (Katja Herbers) when their jobs bring them together in the pilot. "We see him watching her work from a distance and realizing that she's a pragmatic person but also a person who is passionate," said Colter. "As much as she was a skeptic, he's a believer, and those two things are very good for poking holes in all kinds of theories. And they have a good rapport, so I think he sensed that."

That rapport seems poised to come into conflict with David's training for a life in the Catholic Church. "Being a devout man and someone who's pledged himself to celibacy, it's interesting that he'd pick someone that he might have chemistry with," teased Colter, hinting at tension ahead as David and Kristen navigate their working relationship. "You want to see two things that are diametrically opposed, and at the same time somehow connected and attracted to each other, try to work together and keep it professional," he said. But while celibacy is "a strong line" David draws for himself, the actor admitted that his character doesn't present as a typical priest. "When you see him, I don't think people would ever think he's a priest in training," Colter said.

Mike Colter and  Katja Herbers, <em>Evil</em>Mike Colter and Katja Herbers, Evil

The push-and-pull between David and Kristen gives Evil its spark, but it gets its chilling edge from a pair of villains who circle their investigations, blurring the line between paranormal and human. Kristen is visited in her sleep by a sinister demon, George, who threatens her with physical and emotional violence, upending her sense of what's real. Meanwhile, she and David are drawn together by a mysterious man who emerges as a common enemy: Leland Townsend (Michael Emerson), a seemingly unassuming forensic psychologist who turns out to be far more dangerous than he appears. "He's secretly a high order of mischief-maker, a man who wants to create chaos wherever and whenever he can," Emerson told TV Guide.

The Lost alum is no stranger to playing bad guys, but what sets Leland apart, according to the man who plays him, is his complete lack of conscience. There's a playful element to his wickedness. "He has the world on a string," said Emerson. "He's powerful beyond anyone's understanding and can reveal himself at whatever pace he pleases. So he's carefree, in a way."

Beyond the desire to sow chaos, Leland's motives are vague, as is the role he plays in a world that deals equally with menacing demons and the horrors of technology. "Is it evil in terms of the paranormal, or is it evil in terms of social media? We don't even know sometimes," actor Aasif Mandvi told TV Guide. Mandvi plays Ben, a pragmatic carpenter who works with David and accompanies him in the field. "As much as [Leland] is trying to sow disorder, Ben is trying to find order in the world," he said. "So it's a nice polarizing juxtaposition."

Like Kristen, Ben is a skeptic. "All this paranormal stuff, things you can't explain, he doesn't like that. It makes him crazy," said Mandvi. But both Kristen and Ben come from religious backgrounds: Kristen, when asked if she's Catholic early in the pilot, says only, "Not anymore," while Ben comes from a Muslim family. "He has shunned that religion," said Mandvi. "So I think in every character there's an exploration of their personal demons that they're dealing with as well."

The cast praised the show's creators for keeping Evil so focused on the characters in the midst of the horror. "The Kings have been very successful with making sure that it's a character-driven drama and the procedural aspect doesn't take over to the point that you're looking at it from a case-by-case basis," said Colter. "Every episode will have a case that the audience can sort of hold on to, try to go along with and figure it out as well, but it's the relationships between the performers, between the characters, that are going to bring them back week to week and hopefully pull them in so they care."

Evil premieres Thursday, Sept. 26 at 10/9c on CBS.

(Disclosure: TV Guide is owned by CBS Interactive, a division of CBS Corporation.)

Reporting by Sadie Gennis

Mike Colter,  Katja Herbers, and Aasif Mandvi, <em>Evil</em>Mike Colter, Katja Herbers, and Aasif Mandvi, Evil