Michael Emerson

Michael Emerson (Mark Boster / Los Angeles Times)

IT'S DIFFICULT to keep track of all the spiraling story lines in "Lost," but this much viewers know about the enigmatic Benjamin Linus: As a young man, he gassed his father to death along with the rest of the Dharma initiative, and as a father himself, taunted a mercenary into shooting his daughter in the head.

Heartless? Definitely. But a psychopath? Michael Emerson doesn't think so.

"I think of Ben as a man whose mission and responsibilities are so grave that he cannot allow himself much humanity," says Emerson of the role that this year earned him a second Emmy nomination for supporting actor. "He's cold because any trace of warmth makes him vulnerable to his enemies, who we know are powerful and formidable. He's one man against an army of monsters."

Emerson isn't rationalizing, but carving out a no-nonsense character philosophy is about the only thing the 54-year-old actor has been able to do to keep his head wrapped around TV's most infuriating and irresistible drama. Having come off a creatively resurgent fourth season, "Lost" is again contending for Emmy's top drama prize after being absent from the category the last two years.

By now though, Emerson's gotten used to the top-secret, last-minute script arrivals, the never knowing what will happen next. He doesn't know who the "monsters" are, if there are any to begin with, or even what the fate of his character will be when "Lost" returns for Season 5 next January. "Cameras start rolling Monday," he says, relaxed in a tan linen suit on the rooftop patio of his manager's L.A. office early last month. "I guarantee that I won't have a script until Saturday."

But the thinking never stops. "I don't know how Ben sleeps," he says. "Very lightly, I think."

These kinds of insights are what "Lost" executive producers Carlton Cuse and Damon Lindeloff say turned him from a three-episode player to full-time regular. They called on Emerson to play the castaways' mighty adversary having seen his 2001 Emmy-winning guest turn as a creepy serial killer on "The Practice," and kept him after he delivered the table-turning revelation that he was one of the Others in the middle of Season 2.

"It was when he said, 'Got any milk?' after that reveal. We both knew he was a keeper. There's something so incredibly unsettling about his eyes," Lindeloff says. "We used to be really specific in our scripts but now we just write for Ben to look at so-and-so with 'those eyes.' "

"Michael always surprises us with what he gives us. He makes interesting choices that, as a writer, are so inspiring," Cuse adds. "We're like kids at Christmas waiting to see his dailies."

It's been a long road to series TV for Emerson, a Toledo, Ohio, native who studied theater in college but spent the next decade as an illustrator, a family trade. He returned to acting with a vengeance in his mid-30s, working his way from community theater to the Broadway stage, where he appeared in revivals of "The Iceman Cometh" and "Hedda Gabler."

"Theater is my first love. I don't know how I ended up in television, to tell you the truth," he says. Playing Ben, he says, has kept it interesting. Unlike some viewers, who ratings indicate seemed to hit a roadblock between seasons 2 and 3, Emerson never lost faith in the writers.

"People wanted the whole book to be like the first chapter. But the agenda of our writers is much greater," he says, adding that the announcement of a May 2010 end date for the show was "like a great throwing down of the gauntlet."

"You felt the change this season. The urgency, the momentum. Things got darker, more violent, more compressed. The range of the storytelling here is unmatched right now."

And it would make winning an Emmy that much sweeter. "It would feel good," Emerson says. "It would be the only thing that could top getting to move an entire island by yourself."

denise.martin@latimes.com