I didn't break anything," the Vines' frontman, Craig Nicholls, mumbles. He's backstage at the Roxy in Los Angeles, trying to remember what he did last night. "I just remember all this glass. I started making pizza in the microwave around six in the morning. I was really hungry, and I was really out of it; I was hallucinating. Well, not hallucinating, but I didn't really eat. I didn't have any food for a long time before I went onstage. So I was hungry, and I remember there was all this glass. . . ." His voice trails off and his blue eyes cloud over. "Uhhh, maybe I did break something."

He probably did. The Vines are at the tail end of their first extended journey through America, and the strain is showing. In the short time that they have been the toast of the rock world -- six months that have seen the British press anoint them as the best band since Nirvana and their first album, ighly Evolved, debut at the top of the Billboard album chart -- Nicholls has acquired a reputation as a weird little guy. He's become famous for locking himself in the bathroom for three hours before showtime, discussing suicide in interviews and kung-fu-kicking his bassist on the set of a U.K. TV show. At twenty-four, Nicholls says he has already written hundreds of songs. He would rather spend his time in the studio than onstage, but he has spent the past month touring America. It has not helped the mess inside his head any.

Right now, the elfin space cadet sits on the dressing-room couch, writing up the night's set list -- the same dozen or so songs every night, but always in a different order -- consuming bong hits and Red Bull. "How many Red Bulls is too many?" he asks. "I've had two. It doesn't go too well with pot. I don't know if I should have another." He shouldn't.

In the final minutes before the show, Nicholls starts feeling freaked out. You can tell because he gets up and paces, saying, "I'm freaked out." He retreats to a corner of the couch, bong in hand, and curls up into a ball. When one of the roadies asks, "Are you OK to go on?" Nicholls tells him, "I don't know, man." The other Vines don't seem worried. They've heard all this before. A lot. Bassist Patrick Matthews, drummer Hamish Rosser and guitarist Ryan Griffiths drink Victoria beer and debate whether to rip off their shirts onstage the way Nicholls does. "No way," Matthews says. "I'd need Botox in my gut." Nicholls still sits with his head in his hands.

An MC asks the crowd, "Are you ready to rock?" Nicholls lifts his head up and moans, "I am not ready to rock." He heads downstairs to rock anyway. The show is ferocious: Nicholls screams like a man possessed in Nirvana-style rave-ups such as "Get Free" and "Ain't No Room." In a crowd-pleasing version of OutKast's "Ms. Jackson," he sings the chorus over and over, like a psychedelic angel stuck between Australia and the Dirty South. For the final song, "Fuck the World," Nicholls smashes his guitar and jumps into the drum set. He tumbles in the debris, drums and cymbals spilling around him; for the first time all day, he looks like he's having fun.

Ever since they released their debut indie single in Australia last year, the superbly titled "Hot Leather/Sun Child," the Vines have been rocketing to the big time. Along with bands such as the Strokes, the White Stripes and the Hives, they've been acclaimed as leaders of a new modern-rock sound that blows away the bloated Korn-clone cliches of the past few years. In truth, none of these bands really has much in common with one another, but they all get lumped together because they show how rock fans across the world are starved for some new excitement and adrenaline, punk-rock style. Suddenly, the letter K and fake DJs in baggy shorts are out; guitars, leather jackets and the silent E are in. As Griffiths says, "It's a miracle we've gotten through America without anybody introducing us as the Hives."