Michael Emerson finds his dark niche on LOST

'All my actor life I've thought of myself as a comic actor," says Michael Emerson, "and I've ended up playing such dark roles. I don't know how that happened."

Whatever the answer, Emerson has the knack for screen villainy. After coming to a grisly end as Zep Hindle in the first installment of the "Saw" horror franchise, he joined the cast of the castaway drama "Lost," which returns to ABC (Ch. 7) on Thursday at 10 p.m.

Originally contracted for only a handful of episodes, two years later his character, Ben Linus, is the show's most mysterious bad guy. And he's still filming in Hawaii.

"It's grim work," he laughs on the phone from Honolulu. "I used to think it was hard work when I was in the hatch day after day after day, but now I see the beauty of that. At least you're in an air-conditioned building. I have been out in the jungle more than I ever dreamt. And those are hard scenes. When there are a bunch of us trooping around in the jungle, that is a long, hot, buggy day."

Ben's character arc is no picnic. He got to the island before most of the other characters, giving him time to off his abusive dad and assume leadership of the group known as "The Others." Since the crash of Oceanic Flight 815, he has suffered spinal surgery, kidnapping and a crossbow shot to the shoulder.

He started season four as a prisoner of the faction of crash survivors led by John Locke (Terry O'Quinn). Before the pause in the season caused by the writers' strike, fans learned in a flash-forward that Ben makes it off the island and - somehow - recruits Sayid (Naveen Andrews) to work for him as an assassin.

In terms of story details, however, the rate of reveal has been slow. When the show resumes this week, Emerson promises that things get kicking.

"It's going to knock you out when you see that next episode," he says. "It's so full of developments and movement, I can't tell you."

Even his future in professional killing comes into play, he says, with the fates of the "Oceanic Six" - those characters who make it off the island - getting plenty of attention in the season's final episodes.

For Emerson, Ben's future fits his character. "Ben is a man who must sometimes be angry because he's never going to have the quiet happiness of family and home," he says.

"He's always going to be some kind of global warrior. He doesn't get to have the girl."

Fans will remember, however, Ben's foray into romance with Juliet (Elizabeth Mitchell). His wooing tactics included a home-cooked dinner for two, and possibly - maybe - sending her lover, Goodwin (Brett Cullen), on a death mission.

"Whether Ben is capable of a conventional feeling of love I'm not certain about," says Emerson. "It's clear that his feelings for Juliet sort of morphed over into a kind of not-very-pretty possessiveness. Now, I'm not saying Ben sent Goodwin out to die as an act of vengeance, but clearly he's not that unhappy to have Goodwin gone."

Emerson, like all of the actors on the show, discovers his character as he goes. When pressed as to how much he knows about the future of "Lost," he insists he's only about three scripts ahead of the audience.

"I only know up to and including the episode we're shooting," he says.

Rather than presenting a challenge, he says, the experience is freeing. "All I have to do is show up and play the scene at hand, and play it as simply and, in my case, as ambiguously as I can. I leave all that sort of larger-picture thinking to the writers and the audience."

In fact, Emerson says, he's not the encyclopedia of "Lost" facts that one might expect, especially when it comes to the plot lines of his fellow islanders.

"It sounds crazy, but even though I've read the script, I still sometimes don't get what just happened," says Emerson. "I may have a brain defect of some sort because I will just miss obvious things and have to have them explained to me by relatives and children."

When he's finally allowed to come home, his sights are set on New York theater, where he got his break playing the title role in Moises Kaufman's play "The Three Trials of Oscar Wilde."

"I'm so jealous of all the theater that is going on," he says. "It seems to be a really good season in New York - lots of exciting plays - and I think, 'That's where I'm supposed to be!'"

But for now, says Emerson, Ben is giving his acting chops a thorough workout. "The same thing I love doing in the theater, which is to play scenes that crackle, I get to do on 'Lost,'" he says. "As TV roles go, this is a really good one.