LOS ANGELES – Exiting the hotel after an afternoon of press interviews, Seth Numrich seemed taken aback when a handful of autograph seekers approached him.

The Twin Cities native might be a big deal on Broadway, where he has starred in "War Horse" and "Golden Boy," but in Hollywood, he's only slightly more recognizable than the bellhop.

That's likely to change with Sunday's premiere of the AMC series "Turn." Numrich plays Ben Tallmadge, George Washington's chief intelligence officer, whose spy ring helped defeat the British in the Revolutionary War.

"By some miracle, they mistook me for someone else and I got the job," the self-deprecating Numrich said about an hour earlier in the hotel restaurant.

Numrich isn't the star of the series — that honor goes to "Billy Elliot" veteran Jamie Bell, who plays one of Tallmadge's reluctant informers — but he has the most swashbuckling role, one that often finds him with blood on his clothes and fire in his eyes.

Numrich, 27, who made history by becoming the youngest student ever admitted to the prestigious Juilliard School, last appeared on stage opposite Kim Cattrall in a 2013 London production of Tennessee Williams' "Sweet Bird of Youth." He admits that working in television has been an adjustment, one in which he's picking up a lot of tips from his co-star and directors.

"In theater, you get to rehearse several weeks, you memorize everything, and by the time you open, you know what the play is," he said. "In film, it's almost the opposite. You do your work on your own and maybe have a couple of minutes to rehearse. When the camera rolls, you generally don't know what's going to happen. It has the potential to be very spontaneous and alive, which is both exciting and scary."

Numrich, who made his stage debut at the Guthrie Theater in 1999's 'Summer and Smoke," said he also has had to learn to be more subtle.

"The acting isn't any different in that you're still getting to the truth and core of the person you're playing, but on camera you have the luxury of being able to convey things in a much smaller way," he said. "The camera picks up everything."

One person who isn't surprised that Numrich is approaching "Turn" like a freshman student is his father, Twin Cities actor Charles Numrich, who home-schooled both of his sons.

"All of our teaching was grounded in helping them learn how to learn," said the elder Numrich, who co-hosted the 2011 Ivey Awards with Seth. "He has a good idea of the talent that he has and how to take information and adapt it."

Even if "Turn" connects with audiences, don't expect Numrich to completely abandon theater. The relatively short cable season, 10 episodes, provides ample time to sign up for a play.

"This is the longest I've ever been away from the stage, and I do miss it," he said. "I always thought at some point I'd come back to the Twin Cities and do something. I still hope to do that."

njustin@startribune.com • 612-673-7431