The poet's final confessional

Consider the plight of this widower. His wife has chosen to die in a gesture that turns her into a feminist icon and him into a sitting target for the malice of people who claim that she is a martyr to his selfishness. It is only after she has gone, some reckon, that he comes to appreciate the dimensions of his loss. But, of course, she returns from the grave to haunt him - a figure whose silence speaks volumes. These volumes are her posthumous works, which he duly edits and publishes in a lifelong labour of propitiation - or (so his detractors allege) rigid, censoring appropriation.

Consider the plight of this widower. His wife has chosen to die in a gesture that turns her into a feminist icon and him into a sitting target for the malice of people who claim that she is a martyr to his selfishness. It is only after she has gone, some reckon, that he comes to appreciate the dimensions of his loss. But, of course, she returns from the grave to haunt him - a figure whose silence speaks volumes. These volumes are her posthumous works, which he duly edits and publishes in a lifelong labour of propitiation - or (so his detractors allege) rigid, censoring appropriation.

It's not difficult to identify the above figures as Ted Hughes and Sylvia Plath, the American poet who gassed herself, while estranged from her unfaithful husband, in the bitterly cold winter of 1963. The mythic outline of their story, though, bears an uncanny resemblance to the legend that Euripides dramatised in his play, Alcestis. With the difference that in that great, equivocal Greek tragicomedy of 438 BC, the ending is officially a happy one. Admetus, the king whose spouse prolongs his life by sacrificing her own, is eventually reunited with this paragon, thanks to the courageous generosity of his friend Heracles, who literally wrestles Alcestis back from the grip of Death.

Hughes was at work on a free adaptation of this play in the months before he himself died of cancer in 1998. Next Monday, Northern Broadsides gives his version its world premiere. The production is directed by the company's artistic chief, Barrie Rutter, who turned down eager offers from a couple of international festivals so that he could unveil the piece in the poet's native West Yorkshire at the Viaduct Theatre at Dean Clough in Halifax. "My tuning fork is the Calder Valley," the poet told him, a fact to which Rutter attributes the "pithy muscularity" of Hughes's verse. This is also the county where the poet buried his wife, her grave in Heptonstall regularly desecrated by protesters who hack her married surname off the headstone.

There's a very shrewd book by Janet Malcolm on Hughes, Plath and the minefield of biographical interpretation entitled The Silent Woman. It could just as validly have been called The Silent Man. Hughes's reticence on the subject of his marriage was legendary and, to some, further proof of damnation. He broke that silence, in breathtaking fashion, with the publication in 1998 of Birthday Letters. An enthralling, artistically uneven cycle of poems addressed to Plath and full of recontextualising allusions to her own work, it presents the story of their shared life as a ticking time-bomb. The sense of cosmic time-bomb fatalism is so strong that it seems (convincingly or conveniently?) to abolish the very concept of personal "responsibility".

Now from tragic doom we move, with this posthumous adaptation, to tragicomedy. It's a genre that, while often accused of being evasive, can be more guilt-inducingly uncomfortable than tragedy. Indeed, in her one passing reference to Alcestis, Erica Wagner - the author of Ariel's Gift, a fine commentary on Birthday Letters - remarks that in this play "Hughes confronts the accusation levelled against him, that he was responsible for Plath's death, in a way he never had before". How does he achieve this?

The tone of the Greek original is a very tricky. It was first presented as the fourth drama in a tetralogy in the place normally occupied by a bawdy "satyr-play", the raucous, comic relief after all that elevated suffering and purgation. Certainly, the world of the satyr-play erupts into Alcestis in the rambunctious shape of Heracles, who arrives on the desolate scene like some embarrassed mourning-pooper and is only persuaded to stay by the lie that it is another woman who has died. But if the play also contains strong elements of high tragedy, it makes it impossible for us to take the widower at his own estimate. There's a whining self-preoccupation in his grief: you feel he would readily have the play renamed Admetus. Ambiguity surrounds him right to the happy end, since by accepting the veiled silent and as yet unidentified woman from Heracles, he ironically breaks a vow he made to his dying wife.

Not surprisingly, previous adaptors have been tempted to clean up and rehabilitate this equivocal figure. In Gluck's operatic version, Admetus follows Alcestis to the entrance of the Underworld, determined to persuade her to live or to die with her. There's a similar redemptive mutuality at the end of Robert Browning's "Balaustion's Adventure", a long poetic meditation on the play also, intriguingly, written by the widower of a poet-wife. Hughes, by contrast, refuses to take your mind off the question: "What kind of man could possibly allow his wife to die on his behalf? You killed her. Point-blank./ She met the death you dodged", snarls Admetus's father in this new version, defensively justifying his own refusal to perish in his son's stead.

There are moments when the original evidently proved too painful for Hughes. He has left out, for example, this same father's corrosively cynical gibe that Admetus has hit on an ingenious way of achieving immortality: "get each successive wife/ To die for you!" Hughes, who had two partners commit suicide on him (his lover Assia Wevill killing herself and their daughter, Shura in 1969), can't have contemplated that line with equanimity.

In general, though, it's not his nerve in adapting a story so close to home but that he kept his nerve that impresses. Everywhere, there are unsystematic echoes and correspondences, none the less creepy when they are incidental.

A wife who returns from the dead in a piece of theatre and a wife who, in her extraordinary poem "Lady Lazarus", presented herself as a serial suicide, a "theatrical comeback" artiste performing before "the peanut crunching crowd". A dying wife who enjoins her husband to perpetual celibacy and the eight-year-old Sylvia Plath who, after the devastating death of her father, Otto, made her mother sign of a piece of paper on which she'd shakily inscribed the words "I promise never to marry again".

There must have been times when Hughes's imagination linked Plath with another somewhat less amenable Greek heroine: Medea, the woman who avenged herself on her faithless husband by killing their children and a figure Plath herself invoked in one of her late poems, "Edge".

Certainly, her suicide removed the possibility of a life not claustrophobically imprisoned in her myth. As her mother wrote: "She has posthumous fame - at what price to her children and to those of us who loved her so dearly and whom she has trapped into her past." But if some choruses in Alcestis touch on the bleakly invidious position of the survivor, what is more remarkable is that Hughes has projected himself into a story where he is the flawed, guilty party. At the same time, he heightens the celebration aspects of the piece by expanding the satyr play section.

He adds a spirited burlesque episode in which Heracles confronts and overcomes demons from Hughes's own troubled past, freeing the shackled Prometheus - the poet's impaled surrogate in his sequence "Prometheus On His Crag" - and killing the vulture which endlessly gorges on his liver. It's as though, nearing death, Hughes has invited his life-long obsessions round for an end-of-term romp. Existence may be, as Death puts it in this version, "a brief weightlessness - an aberration/ From the status quo", but that should make it all the more appealing to man's rebellious spirit.

When I spoke to Barrie Rutter last week, he was still wondering how to present the climactic reunion between husband and wife. After the veil has been lifted, what expression should she wear? It's a happy ending for Admetus; is it equally happy for her? The ending, Rutter maintains, has to be enigmatic. But he's also surely right to emphasise that this mystery is apprehended within the context of a deep celebration and acceptance of life. As Rutter points out, against all the odds, the last word in the last piece by Ted Hughes is "hope".

Alcestis, Viaduct Theatre, Halifax,19-23 Sept (01422 255266), The Lowry, Salford, 2-7 Oct (0161 876 2000), then Soho Theatre, London from 10 Oct (020-7478 1000)