Theatre Dr Jekyll and Mr Hyde Birmingham Rep

Critics were very much in two minds over Dr Jekyll and Mr Hyde when David Edgar's stage version of the Stevenson classic was premiered at the Barbican in 1991. The decision to present the split self of the hero as a double-act (Simon Russell Beale as a troglodytic Hyde to Roger Allam's proper Jekyll) left the production, most commentators felt, with alter ego all over its face.

There's an odd paradox here. As recent theatrical adaptations of The Mill on the Floss and The Trick Is to Keep Breathing have demonstrated, duplicating or triplicating the central character on stage can be a powerful way of dramatising inner division. But with Stevenson's hero, where the split is so radical that he actually has two identities, this approach proved counter-productive. What got lost was the moral horror and visceral creepiness of the fact that the protagonist is corporeally inseparable from either of these beings.

This has been put right in Bill Alexander's fine production of a version that Edgar has re-worked. A pleasure formerly denied was the spectacle of transformation. Instead of the conjuring trick that swapped Allam for Beale in the railway compartment scene, we now see the excellent David Schofield sink into his seat and mutate in spasms, as if some alien is gouging its way out from within. Features contorting horribly, limbs twisting, he graduates from the prim Jekyll to a contemptuous, combative, working- class Glaswegian troll of a Hyde. The parson (Paul Connolly) in the next seat is at first too wrapped up in his own waffling discourse to notice that his congregation of one has undergone a drastic re-think. "Describe me!" orders Hyde, his indescribable malignity of demeanour achieved by Schofield without any cosmetic aids.

Ruari Murchison's sets are themselves two-faced, constantly on the whirl to take us from the dingy, non-committal facades of Victorian London to the secrets of Jekyll's lair-like dissecting room behind. With Simon Murray whipping up unbearable tension on piano and synthesiser during the fraught countdowns while the potion or its antidote do their grizzly work, there's momentum and old-fashioned melodrama aplenty. You may still feel at times, however, that Edgar's additions threaten to turn it into a tract.

Speaking about The Man Who..., a piece he devised from the neurological writings of Oliver Sacks, Peter Brook once used an intriguing analogy. He said he wanted this show to have a similar relation to Sacks's work as Sophocles's Oedipus Rex has to the writings of Freud. That's to say, he wanted to restore to our sense of these disorders some of the irreducible mystery and powerful human implication that they possessed before they had been professionally elucidated. Edgar has gone about his business in precisely the opposite way. He has taken a potent myth and robbed it of its suggestiveness by too much post-Freudian analysis. Scattering dark family secrets, equipping Jekyll with a one-eyed, widowed sister and a pronounced father-complex, he even shows that it is the hero's reading of his late father's papers that tempts him to make his experiments. Instead of emerging haunted, you come out humming the explication.

To 20 July. Booking: 0121-236 4455

PAUL TAYLOR