Assuming - as one must - that he has more winsome assistants up his sleeve (or hiding in the wings) than meets the eye, you still have to wonder how the illusionist himself manages to be in two places almost at once.

'My critics,' says Copperfield introducing an act called The Fan, 'say I can't manage without a pretty girl, a bit of wind and a great deal of smoke. And I'm going to prove them right.' There is plenty of all three ingredients in his Beyond Imagination show.

In The Fan the illusionist and his inevitably pretty assistant dance their way into a fan, disappear as they move through its whirling blades and reappear in a puff of smoke in the audience.

How does he do it? How does he do the startling trick of instantly swapping places on stage with his assistant? How does he fly? How does he cut himself in half - with an electric saw or a laser beam - and then have the two severed halves move independently of one another? This is one performance where seeing is definitely not believing. Copperfield is the master illusionist as well as the master showman. Whatever else he does - contortions, escape routines, making members of the audience disappear, producing a snowstorm from his fingertips - nothing is as it seems.

It is all delivered with a panache and gently teasing patter that keep you laughing and on the edge of your seat.

I am indebted to the lady in the next seat for the observation that Copperfield has a better figure than his assistants. That probably enhanced the performance for at least half his enraptured audience.

But it does not explain the fascination of the simplest illusions. See this show if you can. David Copperfield, Coliseum, until June 30