At the end of The Sopranos' fifth season, no character was in a worse situation than Christopher Moltisanti. After learning that his fiancee, Adriana, was an FBI mole, he helped engineer her death, briefly resuming his use of heroin to stamp out the guilt. His harrowing journey riveted viewers and won his portrayer, Michael Imperioli, a well-deserved Emmy. "I think Michael is as much the engine of the show now as I am, if not more," costar James Gandolfini says. "Without him, I would be truly fucked."

So where is Christopher's head when the story picks up again? "Something very horrible happened to him, and he was part of it," Imperioli says, sipping from a bottle of Amstel Light in a corner booth at Edward's, near the Tribeca apartment he shares with his wife and three kids. "He's got to find a way to deal with it and move on." The process, as the new season's first episodes reveal, involves assuming more responsibility within the crew run by Gandolfini's Tony Soprano-though vestiges of his trademark hotheadedness remain.

Before landing his signature role, Imperioli, 39, spent a decade acting in indie movies and serving as a regular supporting player for Spike Lee (who filmed Imperioli's Summer of Sam script in 1999). Despite a stray project or three (including pinch-hitting for Jesse L. Martin on Law & Order last spring), The Sopranos has been his primary focus as both an actor and writer for the past seven years. Imperioli's commitment to the show deepened in 2000, when he joined the series's rotation of freelance scriptwriters. "Between the first and second seasons, I wrote a spec script which had a lot of stuff about the afterlife, a dream with a vision of heaven and hell. I had Christopher ODing," he says. "David [Chase] said he was planning on having Christopher getting shot, so we could use all of it."

Although Imperioli has contributed a couple of scripts for each of the subsequent seasons, his commitment to directing plays at Studio Dante, the 68-seat Chelsea theater he cofounded last year with his wife, Victoria, kept him from writing any of the upcoming episodes. For the series's final season in 2007, however, he's been anointed an official staff writer, giving him far more knowledge than his castmates about where the characters will end up. "I have to be very diplomatic and not reveal what I know, and pretend that I don't know much," he says.

The episodes Imperioli has written are among those that deal most specifically with struggles over identity politics within the Italian-American community-in addition to containing some of the series's most pointed retorts to those who claim it furthers negative stereotypes. The recurrence of the identity issue, Imperioli says, is purely coincidental. "Those story lines were David's invention," he says. "My assignments just happened to fall into place with those issues." Still, Imperioli has little patience with Italian-Americans who bash the series. "I find it very hard to believe that the show does damage to people's reputations," he says. "I can't imagine some kid is not going to get accepted by a college because The Sopranos is on HBO."