Magician behind the scenes

Rob Howell trades in visual sleight-of-hand, in elegant secrets, and he's not giving them away. An Olivier Award-winning designer, he believes in the magic of complete illusion. His most recent show, the Madness musical Our House, is, from a purely practical point of view, virtuosic: scenes last for mere minutes, and the Sliding Doors premise (two simultaneous, fast-moving storylines, triggered by an initial choice to do either bad or good) means that the lead, Michael, has to make 28 costume changes in two and a half hours; some in under 10 seconds. Howell tells me how it's done - things are not as they seem - but pleads that I don't pass the information on; it'll spoil it for "them" (as he invariably calls audiences). "I'm depressed that we live in a world where we know how everything's done all the time," he says.

He's also been working on another show about dilemmas, about moral forks in the road. It too has many quick scenes, this time necessitated by flashbacks, but there similarities end: the flashbacks are to wartime Poland, to bleak railway tracks, to Auschwitz-Birkenau. Sophie's Choice, about the terrible memories of a young Polish survivor of the Holocaust, is the first world premiere at the new Royal Opera House. It's based on the 1979 novel by William Styron, but composer and librettist Nicholas Maw was first inspired by seeing the 1982 movie (in which Meryl Streep is luminous as Sophie) and he intends the opera to have a cinematic effect. This means no traditional stage business such as stoppages and blackouts for scene changes; it means fluidity, accompanied by a certain realism and lots of costume and wig changes for Sophie (Austrian mezzo Angelika Kirchschlager). "We're using a lot of the tricks that we learned on Our House," says Howell.

He and Trevor Nunn, who's directing, watched the movie early on, but "when we'd really started working on it we didn't go anywhere near the film".

Sophie's Choice has just had its first technical rehearsal, and the set is strewn around the state-of-the-art backstage area. "The other tricky technical thing," says Howell, "is that Sophie's Choice is a three-hander, and the Royal Opera House has an enormous stage. Most of the story takes place in rooms. Naturalistic small-scale things happen - people open a bottle of wine, have a meal. It would be mad to stretch those." The dusty pink rooms of the Brooklyn boarding house in which Sophie, her unstable Jewish lover Nathan and the narrator, young Southern writer Stingo, meet seem tiny, defensively angular, a bit random. They seem far smaller than the train to Auschwitz, three horribly familiar metalbarred cattle trucks of dark weathered wood. On the floor of one carriage sit a few bereft and battered suitcases. Even among the clutter of sets from La Traviata, The Sleeping Beauty and Die Meistersinger von Nurnberg, the train has a chilling power.

Howell had to find a way to make it all work, and he took his cue from Maw, who told him he'd written one note that rang out every time the Holocaust was mentioned. When Howell started, only Act One and Two and part of Act Three had been written. It's two weeks before opening night and he still hasn't heard the whole opera played by an orchestra. Howell decided that "there should be one thing in my treatment of Auschwitz that should then be present in every other picture, so that by the time we actually arrive at Auschwitz we see it at its most complete, though it's been poisoning and looming over every previous scene." He chose an angle - 16 degrees.

"I was looking at photos of Brooklyn in the Forties, and, of course, photographs of Auschwitz and the Holocaust generally. Then something happened: I noticed that the shots of the Brooklyn Bridge swept down at a particular angle. And that angle cropped up in a lot of photographs of Auschwitz, because in trying to express the enormity and the space - the barbed wire, the railway line or huts disappearing into the distance - the photographer quite often used diminishing perspective. It's weird, but the majority of them seem to be on a similar gradient. So I took that line and folded it around into a box, a holding space that all the other scenes in Sophie's Choice take place within."

The project also, of course, lays all involved - Nunn, Howell, Maw, Sir Simon Rattle - open to charges of aestheticising the Holocaust, making it beautiful. Did he consciously avoid beauty? "It's my job to try and compose the image so that it works," says Howell. "On some level it should be satisfying as a picture. And yet I don't want it to be a satisfying experience." Everything returns to the quality of illusion, which becomes not just about suspension of disbelief, but a moral issue. "I think everybody's just trying work responsibly. The worst thing to do would be to swerve it in some way, swerve dealing with what we have to deal with."