THE Stellar Quines company - who produce drama which aims to speak to the experience of women in our society - have consistently disproved the myth that such theatre is necessarily exclusive of men or stolidly polemical.

The company has never put theatre at the service of political concerns; rather the politics of women's position in society have tended to arise from within works that have been chosen assiduously on their artistic merits.

In 2000 they presented Québécois playwright Jean-Mance Delisle's The Reel Of The Hanged Man, arguably the most fascinating and powerful play of that year.

We may only be in March, but already it seems possible that they are presenting - in The Unconquered by Torben Betts - the best new play, on the Scottish stage, at least, of 2007.

The author of such plays as A Listening Heaven and The Lunatic Queen, Betts has been acclaimed for both the singularity of his vision and the extraordinary poetics of his writing. Liz Lochhead has described him as "just about the most original and extraordinary writer of drama we have".

This latest piece - which has just closed at the Arcola in London, and is currently on an extensive tour of Scotland - can only serve to enhance the reputation of the 38-year-old playwright. Set in a bleakly humorous, two-dimensional, monochrome world not a million miles from our own, the play finds a middle-class family (known only as "Mother", "Father" and "Girl") living a life of comfortable dissatisfaction.

Mother feels no sense of intellectual, emotional or sexual fulfilment whatsoever; yet she remains, as if by default, devoted to her husband. Father, his head forever in a newspaper, is concerned, firstly, with the health of his stocks and shares, and, secondly, with the effects of political events on the stock market. Girl is an archetypal rebellious middle-class teenager, feeling her way towards an ideological articulation of her boredom, anger and resentment.

When this paper world of material abundance and fake happiness is turned upside down by a socialist revolution (the republicanism of which suggests that it is our own House Of Windsor which has been turfed out) and a counter-revolutionary invasion by a neighbouring state, the piece takes on the character of a compelling, cerebral cartoon. It is as if Ralph Steadman had turned his hand to animating one of the late, more explicitly political plays of Harold Pinter.

The counter-revolution brings into the family home the malignant - yet potentially beneficent - presence of an invading soldier. The implications of the soldier's actions in respect of the girl and the family's place in the new order are so impossibly contradictory that the whole nuclear family unit (if not the entire society) seems at risk of being torn down the middle.

There is something peculiarly chilling about seeing appalling acts of abuse being represented in such stark outline. Each of the characters (faces painted white, like clowns) moves in the stilted, unnatural fashion of a puppet. Yet, as in the finest clown theatre, their very strangeness makes them seem, somehow, more human than the characters in the most resolutely realist drama.

In the hands of a lesser writer (to say nothing of a lesser designer and less accomplished directors and actors), the broad-brush irony of the piece could have quickly become predictable and insipid. Yet, Keith McIntyre's black-and-white set and costume designs and the highly stylised movement (created by directors Muriel Romanes and AC Wilson) are so bold and so brilliantly confident that one is entirely seduced by Betts's satirical vision. The uniformly excellent cast rise to the considerable challenges of a curious, weirdly mutated acting style.

However, the key ingredient in the production achieving its unusual emotional and psychological power is Betts's language. The entire script reads like a dark poem of political hope and fear, and, ultimately, of human degradation and defiance. Betts - despite the revolutionary event in his play - is not an optimist, and there is no reason that he should be. If there is hope in his drama, it is that things of beauty (in this case, his exquisite language) can still be forged in the darkness.

If ever we needed proof that the artist to whom the playwright is closest is the poet, it is here.