Hallmark Movies & Mysteries’ Must Solve Sundays continues tonight with the premiere of Kristoffer Polaha and Jill Wagner’s “Mystery 101.”

The new film follows Amy (Wagner), an English professor with a knack for solving whodunnits, and Detective Travis Burke (Polaha) as they work together to solve a few connecting mysteries — a plant heist, a missing student and a dead boyfriend.

Prior to working on this mystery flick, Polaha and Wagner starred together in Hallmark Channel’s “Pearl in Paradise” last year. It was their onscreen chemistry and the audience’s positive reaction to watching them as co-stars that figured into Hallmark’s decision to have them as the “Mystery 101” leads.

“There’s an executive [at Hallmark named] Marybeth Sprows, and she was my executive on ‘Small Town Christmas,’ and then, really, while we were filming ‘Small Town Christmas,’ I got a call from her,” Polaha told International Business Times. “She said, ‘Hey, so, would you be interested in this?’ And they just really liked our chemistry from ‘Pearl in Paradise,’ and I think they wanted to see us matched up again.”

After signing on for the project, the “Dater’s Handbook” actor had some thoughts on how his cop character should best be portrayed. Although it’s a Hallmark movie, Polaha knew it was important to add a little grit to the role.

“I got a little bit of a pop on the wrist from Hallmark. They’re like, ‘Dude, you’re playing him too dark. You gotta lighten it up a little bit. Like, be the Kris Polaha that the Hallmark audience knows and loves, like be charming and stuff,’” he told IBT. “Like, no, but he’s a cop, and this is serious stuff. My goal was to play a cop from a different show that’s gonna enter into this kind of Hallmark world.”

Polaha continued: “So he’s very much a fish out of water at first. He’s hard. He’s like a legit guy. And then, of course, [because of ] Jill’s character, and through the course of the mystery, you’ll see him kind of warm up. It ended up being really charming. I’m pretty pleased with it.”

This isn’t the first time Polaha’s taken on the role of a cop, but it is the first time he’s played one with a dark and serious demeanor. In 2015, he starred opposite Rainn Wilson in Fox’s crime drama, “Backstrom,” as Sergeant Peter Niedermayer.

“What’s funny about that is Niedermayer was very much...into Zen and Buddhism and meditation, and he was a total spiritual, metaphysical cop. The cop I’m playing in [this], Detective Travis Burke, it’s fun because…there’s no tongue in cheek, and we’re not playing cutesy.

“He’s a cop, and he’s good, and he’s tough…And he’s not trying to be charming. Until he starts to realize that the girl he’s trying to help is kind of cute.”

See Polaha’s detective in action when “Mystery 101” premieres on Hallmark Movies & Mysteries on Sunday at 9 p.m. EST.