"I feel pretty comfortable walking away from these songs," Billy Corgan says calmly. It is the afternoon of December 2nd, his last day as the singer, guitarist and songwriter of the Smashing Pumpkins. In a few hours, the band will play its final show for 1,100 adoring fans at Cabaret Metro, the Chicago club where the Pumpkins made their official debut on Oct. 5, 1988. But Corgan, thirty-three, speaks with the certainty of someone who -- after five studio albums and more than twenty-five million records sold worldwide -- has had enough. "I couldn't have gotten through these last two years," he says in his hotel suite, "if I didn't know it was going to come to some conclusion."

That night, Corgan is a different man. At the Metro, the Pumpkins play a four-hour, thirty-five-song marathon covering the extremes of their canon: the epic swirl of the 1991 B side "Starla"; the punk sizzle of "Cash Car Star," from the free Internet LP, Machina II/Friends and Enemies of Modern Music; a nine-song set of acoustic pathos. Special guests include pop-punk rascals the Frogs, Cheap Trick guitarist Rick Nielsen and Corgan's father, guitarist William Corgan, who plays with his son on Billy's memorial hymn for his late mother, "For Martha."

But Corgan, wearing a long silver tunic that makes him look like a papal Ziggy Stardust, can't bear to leave. He brings guitarist James Iha, drummer Jimmy Chamberlin and bassist Melissa Auf Der Maur back onstage for half an hour of "Silverfuck," from 1993's Siamese Dream. "Let's rock one more time," Corgan yells before the last crash of drums and guitars. "Not for you" -- he beams at the crowd -- "because you get it. Let's rock one more time for all those people who don't get it, who don't understand that music overcomes all this fucking bullshit." As the other Pumpkins walk off, waving goodbye, Corgan stays to shake hands and bathe in the fans' love. He bows, hands over his face. When he straightens up and pulls his hands away, the sweat pouring down from his shaven head is overrun with tears.

Chamberlin later says that he ran the gamut of emotions that night: "A myriad of everything the band is - the happiness, the sadness, all of the polar opposites of the heart." The drummer, 36, also started crying when Iha publicly thanked absent bassist D'Arcy Wretzky, who co-founded the band with Corgan and Iha but who left under clouded circumstances in 1999.

"I just wanted to mention her," Iha says a few days after the show. "Regardless of whether she's not playing with us, she's still with us. She was really important to the band." Otherwise, Iha, thirty-two, is not into the "mystification," as he calls it, of the Pumpkins' end. "It makes me self-conscious. I would have just announced it after the last concert. I would have sent out a fax: 'To whom it may concern. . . .' "

In his hotel suite, Corgan recalls the day, last May, near the end of a U.S. tour, when he decided to go public with the news on Los Angeles radio: "I called Kevin Weatherly, the program director at KROQ, and said, 'I have a favor to ask. I want to come in tomorrow and announce the band is breaking up.' He was like, 'Can you repeat that?'

"It was two things," Corgan goes on, running a hand thoughtfully over his clean white scalp. "The band was being judged by this idea that we were still trying to grasp the brass ring, which we knew we weren't." In fact, Corgan, Iha, Chamberlin and D'Arcy had agreed in late 1998 to disband after one more album, Machina/ The Machines of God, and a world tour. "And there were the constant rumors with kids. Every time I stepped out of a door, it was, 'Are you guys breaking up?' I'm not a good liar. It felt weird to look in a kid's eyes and say no."