He quickly shows me a tape of the Hooded Sweatshirt Guys, a running gag. The Guys -- played by writers Jon Glaser and Brian Stack, wearing dark sweatshirts -- rise up silently, eerily, in the lower corners of the screen, late in the show, as O'Brien and Richter sit talking about something else. Mute, goofy, staring presences, they answer all questions by nodding or shaking their heads. Their names are Ira and Jeremy. They apparently come in peace.

O'Brien barely suppresses a smile as he watches the screen. Visual and highly marginal, the Guys clearly approach the essence of comedy for him. "There is no discernible joke," he says. "It's the kind of thing that has to happen after one in the morning. Sometimes I worry about the show, and then I think, It's 12:30 at night, for God's sake. Our motto should be, 'If you have any complaints about the show, you shouldn't be up that late anyway.' "

Five-fifteen p.m.: The hall outside studio 6A. Conan O'Brien, now in tie, dress shirt, and slick suit slacks, has been transformed from room guy into host. He does deep knee bends as the din of the Max Weinberg 7 booms through the double doors. Then he goes in for the warmup.

The audience greets him wildly; O'Brien beams. The 200 faces are primarily white and mainly very young. The average age looks to be about 17. O'Brien bounds up the steps, picks a cute blonde from the seats, and, as the band plays a pounding number, goes into a wild dance. The blonde tries to keep up, then is reduced to laughter. After the song is over, O'Brien, grinning, breathing hard, looks around the audience. They're his.

"Were you frightened by that?" he asks. "Who wet themself?"

He turns to the blonde. "Were you frightened, or was it like a sexual thing?" he asks her.

"Frightened," she says.

O'Brien looks ecstatic. "That's what I was going for," he says.