It may sound banal, but the most important thing, both in film and in the theatre, is the human being - the study of human beings. What you want above all, whether you are doing film or theatre, is to make the audience experience the result as something absolutely alive. The most important thing of all is to create a reflection of reality - to capture a heightened intensity, a distillation of life - and to guide the audience through that magical process.

Of Winners and Losers, interview with Ingmar Bergman

What I have written seems more like the melody line of a piece of music, which I hope with the help of my colleagues to be able to orchestrate during production. On many points I am uncertain... I therefore invite the imagination of the reader or spectator to dispose freely of the material that I have made available.

Preface to the script of Persona, Ingmar Bergman

Persona is one of Ingmar Bergman's most enigmatic films. The idea is notionally very simple: an actress, Elizabeth Vogler, falls silent in the middle of a performance of Elektra. She resumes the performance, but the following day refuses to speak at all. Doctors can find nothing wrong with her, physically or mentally: it seems that she has simply chosen to be mute. Her doctor decides that she should spend the summer at an isolated house with a nurse, Sister Alma. Elizabeth never speaks. Alma never stops speaking. The result is a film that investigates profoundly, and often cruelly, the nature of performance as an existential state of being human.

Meredith Penman (L) and Karen Sibbing in Persona. Photo: Pia Johnson

To attempt to remake Persona as a work of theatre is surely the definition of risk: certainly, director Adena Jacobs and the Fraught Outfit team can't be faulted on their ambition. Such an adventure could so easily end up being a bad imitation, with the haunting performances of Liv Ullman and Bibi Andersson inviting invidious comparison. Yet, miraculously, Fraught Outfit has taken up Bergman's invitation to "dispose freely" of his material, translating it into another form, and, crucially, into an autonomous work.

Persona is signally not an adaptation of Bergman's film. Instead, Jacobs and her collaborators have worked directly from his script, building the theatre from the ground up. The script is slightly edited, and the show is shorter than the film - 70 minutes as opposed to the film's 85 - but the text is all Bergman. The theatre, however, is all Jacobs: and it is arrestingly pure theatre. Fraught Outfit creates the kind of experience that is almost impossible to describe: it's so experientially involving that the ending comes as a shock, as you find yourself surfacing out of the heightened reality of the work.

It left me with the weirdly exhilarating feeling that, without quite knowing what had happened, some kind of inner transformation had taken place while I had been watching it. Perhaps Cathy in Wuthering Heights most memorably describes this sense of untraceable change: "'I've dreamt in my life dreams that have stayed with me ever after, and changed my ideas: they've gone through and through me, like wine through water, and altered the colour of my mind..." Sometimes art does something similar. But it does make it difficult to write about.

The simple premise of Bergman's film, an almost absurdly formal conceit of one character speaking while the other is silent, creates a drama of such complexity and ambiguity that it never seems quite graspable. Alma takes Elizabeth's silence as an invitation on which she projects her fantasy of the perfect listener: she exposes her loneliness, her fears, her shames, and, in a famous monologue, an orgasmic moment of happiness. Then she reads a letter in which she discovers these intimate revelations are, for Elizabeth, an amusing diversion. "I have her confidence and she tells me her troubles large and small. As you can see, I am grabbing all I can get, and as long as she doesn't notice it won't matter..."

After this moment of betrayal, it becomes clear that Elizabeth, who seems at first be to be a passive and benign receptor, is really a predator. As she hungrily absorbs Alma's confessions, she is practising a form of identity theft. Gradually, Alma becomes the blank cipher on which Elizabeth can project identities - wife, mother, actress - which she finds too painful to endure. Alma isn't strong enough to resist her, and the two women merge into a single, disturbing, conflicted self.

In Bergman's film, this instability, even vertigo, of performance is heightened by the alienation of the medium itself. Bergman never lets the audience forget that they are watching a film, a representation of reality, rather than reality itself. Half way through, the projector seems to burn up the negative, and then the film reconstitutes itself; the screenplay finishes with the instructions: The projector stops, the arc lamp is extinguished, the amplifier switched off. The film is taken out and packed into its brown carton. Likewise, Jacobs never lets us forget that we are watching a work of theatre.

What this production exposes is Bergman's essential theatricality, a quality always present in his cinema and, given that he worked extensively as a theatre director, in his life. The realism of cinematic settings is here replaced by theatrical framing. Dayna Morrissey's elegant design exploits the size of the Theatre Works stage, with a defined white floor split by a white curtain that is the width of the space. Backstage is a simulacrum of a Swedish holiday house seen through large paned windows, also curtained, that are framed with blond wood. This creates a flexible playing area that permits both a naked, unadorned stage, when the front curtains are closed, and an almost naturalistic set that opens up distance. The design creates theatrical analogues, if you like, for the close up, medium shot and long shot.

The play moves between perspectiveless close-up in front of the curtain and stylised but naturalistic distance. As the drama turns towards the surreality of dream, these conventions merge and dissolve and reconstitute.  The other aspects of the design - Danny Pettingill's lighting and Russell Goldsmith's extraordinary sound environment - heighten its sense of intense but unstable realism. Something interesting is going on here with time as well - both in the duration of the performance and the passing of time in the drama (the action occurs over a summer): it collapses into a series of distinct sequences that operate like the elisions of dream or memory.

Persona: Meredith Penman (L) and Karen Sibbing. Photo: Pia Johnson

The design frames performances of extraordinary rigor and intelligence. Meredith Penman as Elizabeth begins as a glamorous cipher, a beauty in gold silk whose impassivity is rippled briefly by private laughter, hidden from the nurse, that hints at the cruelty that is to follow. She performs the consummate actor, whose anguish is that she knows, unlike Alma (Karen Sibbing) that while all her behaviour is a performance, the pain that drives it is real. Sibbing's Alma is a masterpiece of subtle layers. At the start of the play she speaks almost as an automon, her self hidden in her role of nurse. She warms through her intimacy with Elizabeth, illuminated by her joy that, at last, someone cares enough to listen to her. After Elizabeth's betrayal, she is almost numb with fury and impotence and, more deeply, a sense of panic that she has lost herself.

One of the most disturbing moments in the film occurs in a dream sequence in which Elizabeth's husband, Mr Vogler (played here by Daniel Schlusser), addresses Alma as his wife. Jacobs reimagines this scene as a raw and desperate sexual encounter which is at once blackly, hilariously grotesque and deeply sad. The physical presence of these three actors is compelling and unfaltering, their portrayals precise and starkly unsentimental; but what drives deep into perception is the felt experience of pain that inhabits each performance. 

This was a show that I couldn't fault in any of its particulars, and which as a whole manifests a lucid complexity that is rare in any medium. Subtle, detailed and truthful, this collaboration transfers the mystery at the heart of Bergman's film intact, while entirely remaking it. As I said, miraculous.

Persona, based on the film by Ingmar Bergman, translated by Keith Bradfield, directed by Adena Jacobs. Conceived by Adena Jacobs, Dayna Morrissey and Danny Pettingill. Set and costumes by Dayna Morrissey, lighting by Danny Pettingill, sound design by Russell Goldsmith. With Meredith Penman, Karen Sibbing, Daniel Schlusser, Jane Montgomery Griffiths (voice over), Hugo Donath/Harrsson Feldman. Fraught Outfit at Theatre Works until May 27.