I left the theatre exhaling through puffed cheeks in that way you only ever do when you have been through an ordeal. Ordeals are hard to recommend.
But in the way other people's misery puts life into perspective, and funerals leave you with a satisfying resolution, Jenny Worton's adaptation of Ingmar Bergman's film at least makes you feel you have earned the right to enjoy life after it has finished.
Set on the bleak shore of a Swedish island, the play's heroine is Karin (Ruth Wilson) who, we quickly learn, was recently discharged from hospital after a mental breakdown. She and her family of three men - husband Martin (Justin Salinger), 16-year-old brother Max (Dimitri Leonidas) and widower father David (Ian McElhinney) - are on holiday. Promises have been made to spend time together, particularly by David, a successful novelist.
What Karin needs, according to her doctor husband, is to behave normally, a prescription apparently based on the theory that being normal leads to feeling normal. Little does Martin know that if Karin's recovery were that easy, Bergman would not have made a film about it.
In 1962, Through a Glass Darkly won the Oscar for best foreign language film. It was made in black and white, and director Michael Attenborough's stage production is almost as monochromatic. Designer Tom Scutt has painted the plaster walls of the family's "holiday island paradise" (a bad omen if ever I heard one) with an impressionistic horizon of breaking waves.
Karin's ailment is never identified but over the course of the play's uninterrupted 90 minutes it is, in Ruth Wilson's utterly convincing performance, quite marvellously depicted. It is as if Wilson has kept the grounded, common sense of Stella Kowalski, who she played in the Donmar's recent revival of A Streetcar Named Desire, and added to it the madness gene that we are told Karin inherited from her dead mother.
One moment she is a rock of reassurance to her angst-ridden brother - as Max, Leonidas does a terrific job transmitting the torment of an adolescent possessed by his emerging sexuality, which explains the porn mag tucked between the pages of his book - and the next moment Karin is away with the fairies. Or are they furies?
Whoever they are, she - and we - can hear them whispering and at times Attenborough's production tips into the mood of a ghost story.
The switch between haunted Karin's stable and scary states sometimes takes place within one sentence of dialogue. It is a portrait that reveals something about suicide that perhaps only the suicidal really understand - that killing yourself is not necessarily a way of running away from this world, but of running towards the next, a place whose existence is a perfectly sane conclusion if you are sensitive enough, or barking enough, to hear beckoning messages from God.
However, the real darkness comes not from Karin but her father, a successful novelist for whom his daughter's suffering could be the subject of the great novel that has always eluded him.
Under creative director Attenborough, the Almeida has stealthily occupied the territory of the psychiatry play. Other theatres make occasional forays but it is the Almeida which has made the land-grab with productions such as Tom & Viv, Mrs Klein and Duet for One, to name but three, and which, more than any other theatre, has placed psychoses and psychologies centre stage.
This then - the only Bergman film the director gave permission to be turned into a play - is the latest in that line. And it could be said that the forthcoming House of Games (based on the David Mamet movie), which features a psychiatrist and a compulsive gambler, is the next.
Through A Glass Darkly is at its most interesting in this context. But it gets nowhere near the rollercoaster highs lows of, say, Tom Kempinski's Duet
for One.
This production's trajectory is more of inexorable decline ending with a clunky coda between father and son that feels like a tacked-on resolution. But like the best plays about madness, it peels away some of the mystery and stigma too. Have fun.
(Tel: 020 7359 4404)