David Giuntoli

Grimm star David Giuntoli says his characters ability to see fairytale monsters  can be a double-edged sword.

"I have to live this double life," he tells TVGuide.com. "I want to keep this fact that I can see strange stuff away from my colleagues and my girlfriend."Exclusive sneak peek video: Grimm takes on Goldilocks

In new NBC series, Giuntoli's character Nick is a police detective who is a descendent of the Brothers Grimm. In the show's world, the classic fairytalewere actually warnings about monsters, and as a Grimm, Nick is able to tell the story book characters from other humans. But not every character Nick encounters is truly a "monster."  

"I can see what lurks beneath," Giuntoli says. "[My character] will see someone morph, but I won't understand what happened and I can't just arrt someone for morphing — they might not be bad. My worldly partner Monroe [is] a reformed Big Bad Wolf."

Watch the interview below for more on the series. Plus: Find out how Giuntoli went from being a reality cast member on Road Rules to starring in prime time.

Grimm airs on Fridays at 9/8c on NBC.