Othello, Donmar Warehouse, Londno

Michael Grandage's production of Othello at the Donmar Warehouse is extraordinarily fresh. The secret of its success lies in the fact that, for once, nothing in Shakespeare's familiar tragedy feels like a foregone conclusion. And that's partly due to the canniness of the casting. Chiwetel Ejiofor as Othello and Ewan McGregor as his nemesis, Iago, go against the notions of how these roles should be played and furnish us with new insights into the meaning of the hero's downfall.

The cynical view of the play is that Othello, the Moorish military outsider, is a fit of murderous jealousy just waiting to happen. Insecure in civilian society, he wraps himself in the security blanket of grandiloquent rhetoric and is more in love with the idea of being loved by a white girl than genuinely in love with Desdemona. Iago, meanwhile, is ill-favoured, sexually impotent, repressed homosexual. He may not know precisely why he wants to destroy the Moor, but he's a dab hand at diabolical planning.

This beautifully lit, sparely staged production is revelatory in the persuasive way it knocks for six this mean-minded interpretation. Ejiofor's Othello exudes charisma and has the kind of gentle spiritual presence that would make you dread doing anything shabby in his presence. And you can see how this would build up resentment in anyone inclined to racism. Never has an Othello been less quick to jealousy, nor more movingly revealed the agony as well as the anger in his mistaken sense of betrayal.

There's nothing deluded, however, in Ejiofor's love for Kelly Reilly's Desdemona. But precisely because he has taken such a risk in marrying her, despite the differences in race and age, it leaves him vulnerable to the insinuations of Iago. Ewan McGregor brings an easy affability to the public side of the role (for once, you can understand why everyone is prepared to trust him) and he drops the mask in order to assume a slightly louche, though insufficiently unsettling, intimacy with the audience in the soliloquies.

With first-rate support from Tom Hiddleston's Cassio and Michelle Fairley's Emilia, this is a terrific Othello and makes one regret all the more that the stars' commitments preclude a transfer, sending the price of tickets on eBay soaring to a reported 1,200 a pair.