"We've had a gag during rehearsals," says Jennings, "that my career has been based entirely on seeing Those Magnificent Men in Their Flying Machines at an impressionable age, whereas with Simon, [he adopts a self-mocking soppy-pious tone] 'I always go for the truth'""We both have moments in the other camp", says Russell Beale - for example, he's given several vertiginously high-definition performances (such as his unforgettable diseased-fop take on Thersites in Troilus and Cressida) and Jennings has produced portrayals that seem to draw on deep personal feeling (such as his brilliant study of Leontes as a dangerous combination of man and arrested boy in Nick Hytner's version of The Winter's Tale). But they agree that this distinction is broadly true.Performing Ben Jonson puts a premium on the chameleonic style of acting. "They don't have a hinterland, these characters" says Russell Beale. "There isn't that sense of a huge landscape behind them of love and loss". He plays Face, who met Jennings's higher-born Subtle when both were on skid row He subsequently got a job as a butler. While the master is away, he installs Subtle (who poses as an alchemist) and scouts round for likely victims.

"There's a lot of tension between them based on class and education," reports Russell Beale, talking about the dynamics of the comic double-act. They have to play an assortment of invented selves, tailored to the particular desires of each client.Hytner's production is in modern dress and finds, says Jennings, "absolutely contemporary equivalents for the yearnings of the dupes". Drugger, the tobacconist who superstitiously seeks advice on how best to arrange his shelves, is introduced to the faddism of feng shui. Kastril, the would-be angry young man who wants to be a champion quarreller, is taught the art of the rap-battle. "Here we are, two little middle-class white boys and we've watched all these videos about rap-battles," laughs Russell Beale. "Yes, you're about to get my nearly-50-year-old Eminem," threatens Jennings There are dizzying changes of tack.

"We've played around with the idea of getting muddled and suddenly swapping performances", he explains.Nowadays, I suggest, the clients would all long to be made famous. "Yes, fame is the modern drug of choice," agrees Russell Beale. And fame (in the sense of becoming a household name) is something that has managed to elude these two superb actors. "Well, we've been slogging away in the theatre, I suppose," says Jennings.