Veteran producer Bridget Carpenter was so impressed by former Game of Thrones actor Jason Momoa’s performance on her upcoming Sundance Channel drama The Red Road that she made this proclamation: “He’s the best actor I’ve ever worked with,” she told EW. “He’s a soulful and deeply prepared actor and this is the finest work I’ve seen him do. It’s unbelievable.”

And Carpenter has been a producer on high-quality shows with plenty of great performances (he resume includes Friday Night Lights, Parenthood and Dead Like Me). In the show, Momoa plays a menacing Native American ex-con who gets out of prison after six years and comes back his hometown in rural New Jersey to run a drug ring run by his father (Tom Sizemore). There he clashes with a compromised local cop (Martin Henderson).

Momoa told us he “flipped out” for the script, which was written by Aaron Guzikowski (Prisoners). “The last time I read something like this was Thrones and I was like: I have to have this role,” he says. “No one is going to beat me on this.”

Momoa, who also starred in the recent Conan the Barbarian reboot, said the resulting performance was his toughest to date. “The hardest thing I had to date was Drogo [on Thrones] and this was infinitely harder,” Momoa says. “I’m 6’5″ and big, but I’m an actor — I’m not going to swing a sword around and rip out people’s throats at my house. The action things are easy for me. I really had to prove to myself to Aaron and Bridget that I really could do it.”

See Momoa’s performance for yourself when The Red Road debuts on Sundance on Feb. 27. Here’s the trailer: