On stage, dancers move hypnotically, writhing in beat to the drums. To the untrained eye, they look perfect. But Boris Eifman, enfant terrible of the St Petersburg arts scene, is not happy. "You've done it three times now and got it wrong each time", he shouts. "This isn't a child's game". Again and again, he pushes his dancers to their limits.

At a time when contemporaries are enjoying their retirement, Boris Eifman is still; "striving for a perfect production". For the past thirty years, he has dominated Russian ballet. Under the Communists, he sought to be; "a free artist in an unfree country". He founded the Soviet Union's first independent ballet company, playing; "dangerous games with the authorities" in order to achieve his objectives. Since the fall of the iron curtain, his fame has spread worldwide. Critics hail him as; "the most innovative, original and creative" of choreographers.

Eifman sees dance as; "the language of the body, which carries within it memories of the history of human development". Artists like him are not simply providing light entertainment. They are unravelling the very secrets of the soul. But this interpretation places a great weight on his shoulders. Choreography is; "a very difficult and painful process" because the inner world he seeks admission to is inherently impenetrable.

Rehearsing one of the major scenes in 'Anna Karenina', he seems consumed with the sense his choreography is flawed. "Something's not working. We need other movements as well", he mutters. Again and again, he runs the dancers through the same short sequence, making only the smallest of changes. Finally, he leaps up and dances the same sequence himself, pursuing that elusive movement. When he finally nails it, he describes the feeling as; "religious ecstasy".

One of the driving forces for Eifman is his complex relationship with the dancers. He seems to despair at his "painful dependence" on performers, recognising the "envy" he feels when he looks upon their young, supple bodies. At the same time, he acknowledges his dancers as "co-authors", as well as "material". He tries to mould them with his; "ideas, emotions and desires".

Now in his 60s, having choreographed 40 ballets and won numerous awards, Eifman believes; "everything important that I'm meant to do is still ahead of me". For years, he's been trying to convert a ruined building in St Petersburg to a Palace of Dance. Doing this will be; "the culminating moment of my life".