YOU HAVE to admire the sheer nerve of Sir Cameron Mackintosh. It takes a certain chutzpah to admit that a multi-million-pound musical isn't working and to relaunch it, four months after its premiere, with all the brouhaha of a traditional first night.

Those who paid to see Martin Guerre Mark I may now feel a legitimate sense of grievance. I also find myself worrying about some of my critical colleagues, who thought everything about Martin Guerre was just hunky-dory the first time around. Where do you go for superlatives when you have already described it as a "masterpiece of musical magic and mystery"?

Enough cynicism, however, for I have some words of my own to eat. I thought Martin Guerre, which seemed at once ponderous and glibly hollow at its original first night, was probably beyond salvation. I now have a hunch that Mackintosh, that most perfectionist of producers, might have turned a flop into a sizeable hit.

I still have reservations, not least about the whole concept of blockbuster shows like this, the theatrical equivalent of airport novels, aimed squarely at a lucrative international market. They have a terrible tendency to po-faced portentousness, and one finds oneself longing for the wit, the warmth and the human scale of the classic musicals of the past.

There is no doubt, however, that Martin Guerre is now slick and dramatically involving, its best tunes have a lush and yearning romanticism, and there are scenes of powerful emotion.

Several new songs have been added, 50 per cent of the lyrics are new (though too many of the rhymes remain pat and predictable), and the show has been restructured to make it both clearer and more plausible.

Declan Donnellan's production still misses a trick by making it instantly clear that the man who returns to the village of Artigat during the religious wars in 16th-century France isn't the real Martin Guerre. But at least the impostor, Arnaud, and the wife of the real Guerre, Bertrande, don't now fall in love with such ridiculous haste.

The romantic story has acquired much greater depth and feeling: Iain Glen is a handsome, rugged hero who radiates an innate decency, and Juliette Caton is now a far more touching figure, with a stronger role in the narrative. The connection between these individual lives and the show's wider study of the murderous hatred between Protestants and Catholics is also more potent.

Nick Ormerod's designs remain an unsatisfying mixture of the high-tech and the drab, but Bob Avian's wonderfully macho stamping choreography brings the whole stage to electrifying life.

I just wish someone had decided to kill off the intolerably sentimental village idiot, Benoit, and the trio of old crones aren't nearly as funny as they seem to think they are.

Martin Guerre still falls a long way short of greatness. But it now has scenes of real power and passion, while its achingly romantic melodies linger in the memory.