Our instinct when watching magicians is to focus on the hands, in the vain hope we may spot their secrets. But to really understand an act’s style, look at the eyes. Take three of The Illusionists, the global magic supergroup that started in 2012 and has an ever-morphing lineup. South Korea’s Yu Ho-jin, billed as “the Manipulator”, has the dreamy gaze of a lover, with the slightest raise of an eyebrow while he caresses his cards. Britain’s James More, “the Showman”, favours a frowning sideways glance, as if even he is perplexed by how he manages to escape from – among other scenarios – a rack of fiery daggers. And Frenchman Enzo “the Unforgettable” Weyne, whom we see stretching his hands through a steel wall, has eyes that flash with childlike wonder at his audacious stunts.

When I meet the three of them, before they start a London residency with four of the other Illusionists, they all remember putting on shows as children. Plenty of kids get a magic set for Christmas but Weyne’s didn’t end up at the back of the toy cupboard. Instead, he realised: “OK, it’s my future.” At 11 he started to build his first stage illusion with his girlfriend. He wields an imaginary saw and laughs at the memory. Soon after leaving school he combined his interests in engineering and architecture to forge a full-time career in magic.

Growing up in South Korea, Yu Ho-jin “didn’t know that magic even existed” until a friend showed him a trick. He assumed his friend had some sort of special powers and was disappointed when he was shown how it worked. Soon, he was creating his own.

Facebook Twitter Pinterest ‘I didn’t know that magic even existed’ … Yu Ho-jin. Photograph: Joan Marcus

More had started out obsessed with the circus. His mum bought him a stick and a spinning plate, he learned how to juggle, and when his school put on a talent show, he took an old shoebox and came up with a magic trick to complete the act. “I called myself James the Dramatic Juggler,” he says with childhood pride. The trick involved a deck of cards, a piece of Blu Tack and a crafty flap. But no one could tell how he’d done it. “The adults didn’t know. That was a powerful thing for me,” he explains. “Suddenly the adults didn’t have the answers.”

They still don’t. When I saw The Illusionists, I was surrounded by beaming, boggled expressions, not least during a trick performed en masse by the audience. On arrival you are handed a sealed envelope containing cards and, during the show, the host asks you to open it up and follow instructions. The trick takes place just before the interval and you could spend all 20 minutes trying to figure it out.

Weyne likes to think of his act as “a game between the magician and the audience”. A sort of meta-magician, he performs a trick, shows the audience how he did it, then adds an extra twist. Yu lets the cards – and sometimes coins – speak for themselves. “For me, your magic is pure,” Weyne tells him. There is certainly poetry in the sleight of hand he practises with his long, elegant fingers. Dressed as a matinee idol with a silk scarf, he makes his cards multiply and vanish. Growing up, he would practise for 13 hours a day. As a teenager, he witnessed the international success of Korea’s breakthrough magician Lee Eun-gyeol. It created “a huge boom” he says. “I am one of the people who followed him.”

How did the other two learn their trade? Weyne says he never bought a book or DVD – he dreamed up his own ideas from the start. More spent his weekends in a magic shop in his home town of Bournemouth. “I used to sit in there for hours. The guy behind the counter, Mike Danata, would demonstrate the tricks to customers. Then he’d teach me.” More went to magic clubs and conventions and “never wanted to do anything else”, he says. A teacher told him “there’s no such thing as Hogwarts”, so he trained as a dancer and performed in holiday parks around the south coast, sometimes sleeping in a tent on the side of the road. With The Illusionists he performs to arena-size audiences of thousands, with three big screens showing close-ups of the tricks. It’s a slick and rousing night of entertainment, if at times cheesy too. In a West End theatre, the staging promises to be rather more intimate.

Facebook Twitter Pinterest ‘A game between the magician and the audience’ … Enzo Weyne. Photograph: Patrik Ratajsky

The seven-strong London lineup features other stars such as “the Futurist” Adam Trent and “the Trickster” Paul Dabek, but there isn’t a single woman among them. More acknowledges that it is still “a very male-dominated artform. When I grew up and was in the young magicians’ club it was all young boys. Much like I suppose football used to be.” The traditional roles offered to women limited them to scantily clad assistants or, like Weyne’s childhood girlfriend, a body to be sawn in two. The Magic Circle, an international society founded in 1905, did not admit female magicians until 1991. Only around 100 of the Magic Circle’s 1,500 members in the UK are women. Things are changing, says More, but “we’re still yet to see a boom in women taking up the art of magic”. The show’s resident director is Hollie England, a former dancer in magic shows and musical theatre. She says a new wave of female magicians are coming through, and points out that previous lineups of The Illusionists have included Josephine Lee and Sabine van Diemen.

Is magic’s fusty, outdated image about to do a disappearing act? The Illusionists will open in London’s West End just up the road from the triumphant Harry Potter and the Cursed Child, whose breathtaking moments of magic are a considerable part of its appeal. The wildly successful Mischief Theatre company will open their magic show, co-created with Penn & Teller, this winter. Entitled Magic Goes Wrong, it promises comically bungled tricks as well as ones that work.

All three of the Illusionists I meet have grown up in the online age. More, at 30, is the oldest. The internet has been invaluable for building their fanbase – More’s tricks on Britain’s Got Talent, some of which feature in The Illusionists, went viral. (In one he spins on a giant spike before seemingly being impaled.) But I wonder if the internet also makes it harder for them to protect their secrets. “A lot of magicians were worried about this,” says Yu. “But even if people know how the trick works, they come to see the show. They are still curious. And the feeling of being curious is connected to being happy. They love to see the magic. This generation knows, it doesn’t really matter how it works. It’s like music.”