One for the Road, New Ambassadors, London

The playwright as power-abuser

In a nightmare, you are being dragged through the dark corridors of some totalitarian institute and one of the guards whispers in your ear the news that you are about to be interrogated by a famous living dramatist. You offer up a silent prayer that the said playwright might turn out to be that nice Alan Bennett, or Michael Frayn or perhaps, best of all, Timberlake Wertenbaker. But, as you're bundled into the room, you perceive that your worst dread has been realised. Turning round to greet you, a faint flicker of superior amusement in those lidded eyes, is Harold Pinter. Still, at 70, an erect tower of testosterone, he moves towards you with a raptor grin. Leaving no time for pauses of any provenance, you wake screaming the house down.

That's the irony about Pinter. Though he's clearly, nay, crusadingly, on the side of liberty, you can feel his imagination revelling in the monstrosity of the sadistic interrogators he creates, an unnerving brigade who stretch from Goldberg and McCann to the pair of charmers in The New World Order. If you were a dictator, you would kill to have him on your payroll, that's for sure. Now, for one week only, you can see Pinter perform the role of Nicolas, the interrogator/torturer in his 1984 play, One for the Road which has been brought to the West End's New Ambassadors from the Gate Theatre, Dublin in a meticulously well-judged production by Robin Lefevre.

Running for about 35 minutes, the piece shows Nicolas in separate conversations with three of his victims: a tortured dissident; the dissident's wife who has been subjected to multiple rape; and their little boy, whom Nicolas eventually has put to death – a fact he casually tosses to the father, via a lethal change of tense, in the play's last line.

In Lefevre's production, though, before any of these encounters, the spotlight lingers on Pinter's brooding torturer, downing the first of many glasses of whisky. It gives you a preview of the private demons behind the mask of patriotic certainty, of a lonely, troubled figure who has found a home by subsuming himself entirely in the bogus family of the state.

This perception informs the rest of our view of Pinter's Nicolas. No one could time better the breezy barbed banter and chap-to-chap playfulness of the way he toys with his victim Victor (Lloyd Hutchinson), nor the matey, tongue-out insinuations, or sudden alarming switches of register from flirty to furious.

But he also rightly makes you wonder why, if there is strength in silence, Nicolas is squandering so many words on this largely mute dissident whose shoulders he massages and whose chest he touches as if possessed by some perverted erotic longing. It's significant that his most violent nose-to-nose outburst is against the wife (Indira Varma), whom he sees as having betrayed her patriot father. Fathers mean too much to Nicolas and drive him to extremes, whether in idolising the country's military dictator, or in punishing Victor by brutally annihilating the father-son bond.

Eerie glimpses of doors ajar, spilling light at varying depths in the darkness, create, in Liz Ashcroft's design, the sense of a vast nightmare network of repression. But the main spectacle is that of Pinter. Patrick Marber, one of his creative successors, told me last year that when playwrights act in their own works, there's always a special power because they possess the language; but with Pinter, that power is squared when he plays one of his own power-abusers. You have until Saturday to witness this remarkable phenomenon.

To 7 July (020-7836 6111)