Peribanez, Young Vic, London, ****

It's one of the most striking and potent pieces of doubling I've witnessed. At the Young Vic, the muscled, charismatic David Harewood is currently tackling two roles for the price of one. He plays an aristocratic military Commander, and he also appears as the horse ridden by the peasant farmer whose honour the Commander has mortally offended by having designs on his new wife. To get him out of the way, the peasant is rapidly promoted to the rank of captain of a company of soldiers.

It's one of the most striking and potent pieces of doubling I've witnessed. At the Young Vic, the muscled, charismatic David Harewood is currently tackling two roles for the price of one. He plays an aristocratic military Commander, and he also appears as the horse ridden by the peasant farmer whose honour the Commander has mortally offended by having designs on his new wife. To get him out of the way, the peasant is rapidly promoted to the rank of captain of a company of soldiers.

The irony of this strategic social elevation, and of the way it is bound to recoil bloodily on the Commander, are beautifully crystallised in that image of the little farmer borne on the shoulders of the same actor who plays his devious superior. The symbolism of it – at once so simple and so penetrating – is a token of the astuteness of Rufus Norris's compelling and persuasive account of Peribanez by the Spanish Golden Age master (and Shakespeare's contemporary), Lope de Vega.

When English actors broach the Hispanic repertoire, whether in Renaissance drama or in Lorca, the result can be embarrassing, tantamount to watching a poodle attempt an impersonation of a bull. Norris gets round that problem by using a clutch of earthy Celts to create a modern-dress peasant community. The polymetric verse of the original becomes, in Tanya Ronder's new version, powerfully direct prose dialogue that can rise to the poetic, if required, without ever forcing the actors into borrowed or unnatural-seeming attitudes.

Peribanez, the eponymous farmer, is given a captivating Scots grittiness by the wonderful Michael Nardone. To the slurred, raucous sounds of a local band, the celebrations for his wedding to Jackie Morrison's lovely, shrewd Casilda are first seen in silhouette through paper curtains. Ian MacNeil's two-tier set facilitates not just pointed diagrams of the relationship between high and low in this viciously snobbish society, but also moments when scenes can be juxtaposed in a state of suspended and telling simultaneity.

One of the virtues of the play, and of the production, is the sense we get that impending tragedy can coexist with the kind of dignity-puncturing comedy that is here furnished by the chalk-and-cheese rivals for the Commander's ear – Mark Lockyer's snooty stoat of an adjutant, and his loon-eyed, low-life adviser Lujan (Paul Hamilton), who never knows whether he will be stroked or struck by his boss.

The meaning of honour is probed in this piece. Scornful of the mere idea that it can be found in a farmer, the Commander is none the less prepared to knight Peribanez and give him a commission in order to remove him from home. But that ceremonial act, which involves the peasant swearing to wear his sword in defence of his honour, ironically gives Peribanez the gentlemanly entitlement to slay the Commander. In scenes of sudden savagery, Norris's production underlines how the neatness of this proposition is thrown into disarray by cock-ups, bloodshed and trauma.

In the original, there is a happy ending. But though Peribanez receives a formal pardon from the king, the troubled conclusion in this version brings to mind the T S Eliot line, "After such knowledge, what forgiveness?". The Queen's offer to lend the shell-shocked Casilda four of her dresses feels grotesquely tactless, while you feel that the King may be doing Peribanez a favour by despatching him to the war in which he is likely to lose his life.

To 7 June (020-7928 6363)