HERE is how you turn the proscenium stage of the Duke of York's into an arena for the kind of close-range combat you'd expect in a boxing ring. Rip up the old stage and move it into the stalls. Then, using plenty of scaffolding, build a new stalls, dress and upper circle round the rest of the theatre. That way the audience is on three tiers and four sides. Next, lay down metal gangways inside the new, enlarged auditorium and place audience members between the gangways and central platform. Their heads poke up close to the actors' feet.

Stephen Daldry's revival of Ron Hutchinson's enthralling play Rat in the Skull, which opens the Royal Court's Classics Season in the West End, is an event before it even begins. What follows is no disappointment. Police hurtle along gangways, floodlights glare under the grilles, and spotlights whirl overhead, before fixing on mug shots of Rufus Sewell's badly beaten face. As the terrorist, Roche, Sewell swivels on a lone chair on a earthy platform and drags on his cigarette. This is the interview room at Paddington Green Police Station. Daldry's startling refurbishment of the Duke of York's - the designer here is William Dudley - gives what follows the sort of focus traditionally reserved for contestants on Mastermind. Except here Sewell scores by not answering the questions.

A year after the cease-fire, you wonder if the interrogation of an IRA bomber by an RUC officer, and the subsequent interrogation of the RUC officer by a Superintendent of the Met, will hold the fascination it did in 1984. If you are someone who wished the Irish problem would just go away, your position is dramatised by Hutchinson with great canniness: the mainland's relationship to the province is one of his principal themes. It comes as a jolt to be reminded how things were in the 1980s. But Hutchinson's play digs so deep it can hardly date. As young PC Naylor, played with a hilarious squeaky plaintiveness by Pearce Quigley, says: "We are approaching Belfast airport. Please set your watches back 300 years." The terrorist and the RUC officer (Tony Doyle) are products of history: what they say will have shelf-life.

Daldry directs performances to match the writing. Whether tauntingly defiant or quivering with suppressed feeling, the rangy, unshaven Sewell makes a perfect foil for the consummately controlled rhetoric of Doyle's RUC officer. Part of the strength of Hutchinson's play is that, in this surprising web of relationships, Roche the terrorist and Nelson the RUC officer have more in common than the RUC officer and the Metropolitan police. "I know him," says Nelson, "like he knows me." Belfast may be 40 minutes by air from London but in this graphically accurate, funny and impassioned play, it can appear as distant as Canberra. It's a thrilling piece of theatre. Go and see it.

There is no elaborate staging in the Northern Broadsides touring production of Antony and Cleopatra. There's a rostrum at one end, some cloth, a couple of cushions and that's it. The conference between the triumvirate at Misenum is a few guys in suits sitting in chairs, two of whom look as if they stepped off the commuter train an hour before. The revels on Pompey's galley take place round a trestle table and two benches. Northern Broadsides strip plenty away. What they offer in place is a vigorously acted version of the text. Who needs scenery, props, background music or lighting cues? None of them can rival the visual grandeur of Antony (Barrie Rutter) spelling out to Cleopatra (Ishia Bennison) as a matter of fact why he had to follow her from battle:

"Egypt, thou knew'st too well

My heart was to thy rudder tied by th'strings,

And thou should'st tow me after."

In the Northern Broadsides version of the Battle of Actium, there are no oars, sails or masts. The two sides stand either end of the hall, wearing plain uniforms, like rival companies of refuse collectors. One side wears orange, the other blue. The battle is a percussive one. They hammer threateningly on oil barrels and plastic containers (orange and blue, too). When an orange guy crosses the hall and drums with the blue guys, we all know Antony's lost.

No one lingers. If the actors get dressing rooms on tour, you imagine there are signs up, saying: "Get On With It"; "No Acting". In this fresh, abrasive context, there's no room for displays of sensibility, which so often slide in, like double-glazing, between us and the play. We act like jurors. Argument is prized so highly, that in this flinty atmosphere, the poetry suddenly takes flight.

This, then, is a bare, fast, humorous rendition. When Cleopatra strikes the messenger, Ishia Bennison whacks him in the stomach. There's nothing middle-class about her. She'd be just as at home in an Alexandrian council estate as in her palace. When Dave Hill, as a weary seen-it-all Enobarbus, tells Agrippa and Maecenas of the barge Cleopatra sat in, it's no purple passage: they've asked him, so he'll tell them. When Antony has stabbed himself, Cleopatra smothers him with kisses, but the brisk, plain-speaking Rutter objects: "I'm dying, Egypt." He wants some air. The approach is assured and consistent: with it, Northern Broadsides challenge the larger subsidised companies with a simplicity, directness and house style that does Shakespeare good service.

Martin Duncan, artistic director of Nottingham Playhouse, has turned the 1920 expressionist film The Cabinet of Doktor Caligari into an 80- minute play that keeps suggesting it's on to something intriguing without ever deciding what. There's zithery, spooky music, abstract settings, dancers and acrobats, sketchily drawn characters and a lofty, sonorous Caligari from Matthew Kelly. But these disparate elements don't fuse into a style. If Duncan had gone one step further he might have made it a musical. With its melodramatic story-line, theatrical period setting, cinematic origins, and ample scope for pathos, it's a natural for Andrew Lloyd Webber.

'Rat in the Skull': Duke of York's, WC2, 0171 836 5122, to 18 Nov. 'Antony and Cleopatra': Warwick Arts Centre, 01203 524 524, then touring. 'Dr Caligari': Nottingham Playhouse, 0115 941 9419, to 21 Oct; then Lyric, W6, 0181 741 2311.