During each 20 minutes, Fisher will completely fill the huge space, from top to bottom, with constructions made from his beloved lightweight materials. Much of what you see will be adapted from the technology of racing yachts, mountaineering equipment, parachutes, gliders, and of course the tensile structures of which the Dome itself is the supreme example. To these, add light - which Fisher handles almost as if it were a tangible material. All those performers rising from the floor and flying down from the roof, will assemble what is meant to be an amazing edifice as part of the storyline, then completely remove it again for each show. What makes this different from the rock extravaganzas he habitually designs is that there will be few of the remote-controlled gizmos, and none of the giant inflatable figures, without which no Stones tour, for instance, would be complete.
"The major architectural determinant is that we treat the arena as an urban space," says Fisher. "So there is no sign of the show when it's not on. It completely disappears." Note his use of the present tense. Fisher has it completely worked out. In his head, it's already as real as the various rock shows he currently has touring the world in their fleets of giant trucks.
It is important at this stage to recall Pink Floyd's "The Wall". That production, the culmination of Roger Waters' then leadership of the band at the start of the 1980s, happened to involve the physical creation and destruction of the eponymous barrier within the timespan of the show. Fisher is happy to pay tribute to it: "I learned a lot about stagecraft from Roger Waters," he says. "It's to do with having a series of big visual spectacles that, taken sequentially, make up a narrative."
Fisher is thinking about the choreography of football matches as he plans his production. The almost epic sweep of a big match, played out to the noise of the crowd, is what engages him. He envisages "fabulously exaggerated" costumes, but the acrobats - 80 per show - are effectively mimes, acting to the Gabriel soundtrack. More he will not divulge, although he lets slip at one point that there is a subplot of a love story in there somewhere. The storyline, he insists, will remain a secret right up to opening night on December 31, 1999.
Fisher and Mike Davies, the architect partner of Richard Rogers responsible for the Dome, trained together at London's iconoclastic Architectural Association back in its plug-in, pop-up days when the future seemed infinitely inflatable. The two men get on, and so they should on this project - surely the ultimate Sixties trip. Back then, as Fisher recalls, people like the American inventor Richard Buckminster "Bucky" Fuller proposed creating whole cities under vast climate-controlling domes. And now at last they've been given the chance to do it. For Fisher and Davies, the Dome is their take on that Bucky concept. They don't see it as a building so much as a controlling enclosure. Like the circus Big Top with which it is often compared, but on a Piranesian scale. Beyond a certain level, he observes, size simply becomes a thing in itself.
So right does he seem for the task, that one is inclined to forget that Fisher is a relatively late arrival at the Dome. For a while, the central arena was going to be given over to the impresario Sir Cameron Mackintosh. But he devised a show requiring so many child-actors - allegedly 3,000 of them, 1,000 of them on stage at a time - that a complete new school would have had to be built on the site, as well as stables for 200 horses, all to perform in a vast new circular high-technology theatre costing twice as much as the Dome above it. It very nearly happened: but Mackintosh himself appeared relieved when the idea was finally axed late last year. Enter Fisher, yoked with the musician Peter Gabriel and the choreographer Micha Bergese: and exit the idea of a huge theatre drum blocking all the prime views at the centre of the Dome.
The perfomers will be working at heights many times greater than any usually encountered by circus acrobats, and certainly higher than the currently fashionable "art circus" actors from outfits like Cirque du Soleil, who have previously worked in the Albert Hall and who will be advising on this show. Fisher's mention of gliding technology prompts the question: will his performers really fly? He sighs. "You could without difficulty fly in that space. But the idea of an out-of-control aircraft crashing into a crowd of 15,000 is not attractive. No, everyone will be fully secured. This is a resolutely low-tech show." A pause, and he brightens. "Of course, a lot of them will seem to fly."
