Patrick Dempsey finally gets to use his real accent in 'Thanksgiving'.

The 'Grey's Anatomy' and 'Enchanted' star plays Sheriff Eric Newlon in Eli Roth's new holiday horror as he investigates a series of gruesome murders in Plymouth, Massachusetts, and it marks the first time he's ever been able to speak in his actual voice on screen.

Filmmaker Roth told MovieWeb: "Boston guys, we love the accent. And even if you don't have it, you still love it, or you grew up with it.

"Certain kids had it like wicked hardcore, other kids less so. And when Patrick Dempsey reached out to me about being in the film, he said, 'Should I do a New England accent?'

"I was like, 'Well, one of my pet peeves, I hate movies where someone tries to do a Boston accent and fails, it ruins the movie for me.'

"And he goes, 'No, no, I grew up in Maine. I got like a light accent.' And I'm like, 'Are you? That's perfect.' He goes, 'I had to lose that accent when I became an actor.'

"This is the first time Patrick Dempsey ever used his real accent in a film. He really talks like that."

The mysterious killer in the movie is nicknamed John Caver and sports a mask inspired by the well-known pilgrim and first governor of Plymouth colony.

Roth admitted there was another New England connection when another cast member revealed she was actually one of his direct descendants.

Recalling her audition, he added: "I'm like, 'How are you so good?' 'She's like, I'm from Hanover.'

"She goes, 'Not only that. I'm a descendant of John Carver. He's an uncle.' I'm like, what? She's a direct descendant.

"The woman who is in the diner is a direct descendant of John Carver. So we have people with authentic accents."