Drama doesn't come more urgently political than in the work of the Belarus Free Theatre. Banned in its home country, where all official theatre is state-run, the company rehearses and performs in secret, its productions and very existence acts of cultural defiance.

In the first of these two short plays, performed in Russian with English surtitles, they mine the work of Harold Pinter for thrilling resonances, thrusting jagged shards of scenes and dialogue from his plays among extracts from Pinter's Nobel Prize lecture and testimonies of the victims of human rights abuses and political prisoners.

Beneath a photograph of Pinter's own watchful eyes, the cast of seven, dressed in grey suits and directed by Vladimir Scherban, create a nightmarish kaleidoscope of darkness, light and blood-red. Their hands are stained as if by stigmata; their delivery is packed with punchy aggression, and the menace of Pinter's writing becomes uncompromisingly overt. In a scene from The Homecoming an actor spectacularly sprays the stage with saliva before burying his face in a dog's bowl. A conversation from Old Times becomes increasingly interrogative, and a wet finger run round the rim of brandy glass, producing a high-pitched wail, turns an innocent-seeming object into the source of a sound that is disturbingly redolent of agony.

Beneath plastic sheeting, figures writhe and struggle during an account, from Ashes to Ashes, of babies snatched from their mother's arms; naked or semi-naked torture victims are blindfolded or taunted with fire.

Generation Jeans, written, directed and performed by the company founder Nikolai Khalezin, is less theatrically interesting, though the story it tells remains fascinating. Largely autobiographical, it explores both the Belarusian counterculture that has taken denim and Western rock'n'roll music as its emblems, and Khalezin's own experiences when imprisoned in claustrophic conditions after a demonstration.

An onstage DJ, Lavr Berzhanin, plays Led Zeppelin and the Rolling Stones while Khalezin traces his youthful dabbling in black marketeering, his acts of defiance and their personal emotional cost, and explains how, in Belarus, jeans have become a symbol of freedom - “a little bit of America and Britain”. His performance style could be more dynamic and a little more variety of pace would be welcome, but his story rewards attention. And, together, these two plays offer a rare opportunity to see political art truly in action.

Box office: 0870 4296883. To Feb 23

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