The dancing caterpillar, a role Wheeldon created especially for Underwood, is a womanising predator with sinuous limbs. No stumpy little larva stubs on this slithery creature. Underwood's nocturnal scene, with deep blue lighting and insistent Middle Eastern drums, contains more than a hint of danger.

"I drug Alice with magic mushrooms," says Underwood. "To do that, you sort of seduce her to come into your persuasion, with a seductive, sexual dance, and then you poison her so she hallucinates. He's a bad guy, a villain."

That's exactly the kind of role he craves. "I immediately connected with it. I have quite a powerful stage presence. I don't want to say I'm intimidating, but I'm fearless, so I'm happy to go to that place."

Perhaps Underwood's bold approach stems from the way he landed in ballet, falling into the art form in a mixture of sadness, shock and joy. He was 14 and a student at Suitland High School in Prince George's County, Maryland, in the US. He wanted to get into the school's Centre for the Visual and Performing Arts, but he failed his acting audition.

He could do the splits, though, and that caught the teachers' attention. Underwood found himself suddenly thrust into the dance programme.

"It was love at first sight," he says of his discovery of dance. He went on to join the Dance Theatre of Harlem and American Ballet Theatre, and he arrived at the Royal Ballet in 2007.

"I said to myself, 'Eric, you only dance once, and you'd love a chance to dance with such a huge, reputable company'," Underwood says, explaining his move.

It was a propitious one. Wheeldon and Wayne McGregor created roles for Underwood in several ballets. He'll be featured in the Royal Ballet's production of , which the company will stage at the John F. Kennedy Centre for the Performing Arts in June.

Underwood is so enamoured of his adopted home that he became a British citizen, ensuring he can remain in England after he retires from the stage. He wouldn't give his age, but he's preparing - wisely - for the inevitable end of his dance career. He recently choreographed and danced in a short film on climate change for English fashion designer Vivienne Westwood.

The short features lots of terrific hats and pointe shoes, and an environmental message that's right on trend. Fashion on film is one thing, but full-length ballets are rather new to the big screen. In recent years, digital projections of live performances, beamed by satellite, have brought ballets by some of the world's most prestigious companies, such as the Royal Ballet and Moscow's Bolshoi Ballet, into cinemas with the equipment to receive them.

What's it like for a dancer to know his performance will be captured and projected larger than life, with no do-overs? "I think it's fantastic," says Underwood. "Though for the dancers, it's a bit more pressure. You're not usually doing it in front of the whole world."

Still, Underwood says, he plans to dance for the world with his usual abandon. "It's better if I just go onstage and I'm unconcerned about the cameras and angles, and I just dance. That's more powerful than someone who is calculating every second," he says.

"Personally, onstage is where I feel the most at home, the most relaxed and casual. I'm doing what I love and people just happen to be watching it."