Patrick McCabe's new play is haunted by a part of Ireland that has become a casualty of the country's astonishing rapid development, writes John Kenny.

Like those invigilating cathedral gargoyles originally designed in good faith to ward off demons, our religious psychology is dominated, not by holy ghosts, but by the threat of the darker angels, the tormented ones, the haunted, those or that which just will not seem to quite die.

The regular figuration of this psychology in art, literature and popular culture may by now beggar actual belief, but by God it's still interesting. We very often find ourselves in the revealing position of the fabled old Irish woman who was asked by the anthropologist if she believed in the fairies: "Indeed and I do not," came the dismissal, "but sure they're there all the same."

The air of the gothic in Pat McCabe's work is fundamental to a sensibility which finds atheism a potentially arid position for the imagination. Given the title of his new play, does he directly believe in ghosts or revenants? "I'd be with the old woman. I don't disbelieve in them."

Developed and rehearsed in Monaghan town immediately before moving to Galway in preparation for its world premiere at the Galway Arts Festival, The Revenant is, McCabe insists, very much a collaborative project, and there are therefore three further people to query about fundamentals: the director, Joe O'Byrne, the lone actor, Peter Trant, and the music deviser (with help from Herb Macken), Gavin Friday. And, as it turns out, there is more than one way to give skin to more than one kind of ghost.

McCabe and Friday are ideal interviewees. Press go, and away they go. These two can afford a little relaxed distance, for their work on The Revenant is largely done. O'Byrne and Trant, however, are in the midst of their part of the work, and their somewhat more cautious responses testify to the fatiguing one-to-one experience they are presently undergoing daily.

O'Byrne and McCabe know each other since the mid-1980s when they both lived in Balbriggan. McCabe recalls a juncture when discussions about theatre in his circle were suddenly moving from drink-talk into actualisation, and O'Byrne was a motivating force in this.

O'Byrne became interested in directing when he lived in Germany for a few years (he still regularly lives for periods in Berlin), and by the late 1980s he was both writing and directing very successful theatre with the new company he founded called Co-Motion, which quickly gained a reputation for strong alliances of different media and forms, whereby music, especially, and the sheer physicality of human presence in live performance were explored without at all detracting from carefully scripted words and strong storylines.

In 1987, O'Byrne asked McCabe to write a play, and Frank Pig Says Hello emerged for Co-Motion alongside, rather than subsequent to, McCabe's related breakthrough novel of the same year, The Butcher Boy (1992). A new O'Byrne production of this first collaboration between the two is currently touring.

Their second collaboration was Loco County Lonesome (1994), a play which originally didn't attract the audience they thought it might, but which was subsequently better received in a revamped second version.

Then came their brilliantly antic stage version of McCabe's own masterwork, The Dead School (1995), which Macnas produced for the 1998 Galway Arts Festival. They worked very closely together on that project, and their enduring enthusiasm and affection for the show is perceptible when they speak of it now (lamentably, inherent production costs meant that The Dead School didn't tour abroad at the time, and the show has never been revisited by themselves or any other company).

While the scale is much smaller than with The Dead School, McCabe is closely involved in preparations for The Revenant because "this is a different animal, it's very personal and organic. Peter and I know each other, so we can choreograph and get the material organised."

Trant and McCabe have a shared background. They went to the same school, hooked up later when both had moved to London, and both have subsequently returned to their native Monaghan where they are closely engaged with their locale (they are two of the organisers of the first Flat Lake Literary and Arts Festival scheduled for Hilton Park near Clones in August).

Though they are wary of nostalgia, they have found the pace of change in the contemporary Ireland they returned to particularly astonishing. Mutually affected, Trant remembers McCabe suggesting that they do some work together, and the initial idea was that they would develop a specific vehicle for Trant's voice. Their plans were modest. McCabe would write and direct, Trant would act, and they'd put the thing on in a pub or some other small venue. An exhibition was to accompany the piece, comprised of some of Trant's photography, which, McCabe emphasises, was crucial to the development of the new work: "He has these acid lemons and saturated crimsons over the sky against the crumbling backdrop of the old town, which would have been the imaginative landscape I inhabited."

'The revenant' had its beginnings in these psychedelic colours, though ultimately McCabe sees the tint of the play as "a kind of gothic grey, that feel, the colour of ash, like a life-force has been removed from a town, like the pulse-beat of imagination has gone some place else".

McCabe eventually sent the script to his established director-collaborator, and O'Byrne immediately suggested that it would be perfect for a Gavin Friday soundtrack. McCabe and Friday met in Dublin in the early 1990s and, especially through a discovery of similar musical interests, they quickly developed what Friday describes as a "spontaneously creative" friendship.

"We found we spoke the same language," he says, "but in a different way." From the start the two had "boxing matches with ideas, games of emotional and intellectual ping-pong", and they often plotted "these mad plays".

McCabe did the sleeve notes for Friday's album Shag Tobacco (1995), and, somewhat to his surprise since he initially thought he was being brought in to help with the soundtrack, Friday found himself 10 years later taking what turned out to be a show-stealing part for Neil Jordan's film version of McCabe's Breakfast on Pluto (1998).

Friday scored music for the original radio version of McCabe's dementedly ingenious serial novel Emerald Germs of Ireland (2001), and while that involved some direct responses to the text, his approach to music for The Revenant is suggestive for much of what the audience might expect. He felt that it was important to avoid anything too literal. Fascinated by the strange personality of the play's single character, he went "straight to the child in this guy" and wrote the main piece, Dreamland, which miraculously echoed a song title McCabe had silently associated with the play in its early stages. Dreamland is essentially about "the place a hurt child goes to, and the lyrics have an evocative childlike or dreamlike melody - it's melodramatic in a sort of sad way".

From the way the four talk about their respective participation in the production, it becomes evident that we should expect two types of ghost from The Revenant. Since the show (to call it a play doesn't seem to quite accommodate its multi-dimensions) is about what McCabe calls a "metaphysical conjuror" who is busy remembering and imagining without distinction, and who is the focus for a treatment of good and evil, it is an existential work about horror. O'Byrne suggests that with horror "you are and you aren't in the real world. You're somewhere in between, with a foot in each."

Nevertheless, and this is McCabe's modal signature, the conjuring happens within a social actuality, in this case that of contemporary apartments and transformed townscapes, and, in keeping with this, O'Byrne is keen to stress that the presence of a single character does not mean that we should anticipate a monologue.

Rather, the show is "a dialogue where only one person speaks", and the obsessive single voice which is a McCabe perennial is counter-pointed and abetted over the 65 minutes of The Revenant by other varieties of sound and image and by a wider milieu. Visibly intense in his immersion in his role, Trant encapsulates the collaborators' visceral rather than conceptual intent on all levels: "This whole process is about things going and returning and mourning and loss. Take a walk around our small town and it becomes apparent that what was is no more, and maybe we're trying to conjure up some of that and bring it back."

The dictionary definition of revenant is "a person who has returned, especially supposedly from the dead". The Revenant will surely have some intriguing things to say about the extraordinarily dismissive quick turning of the rational screw inscribed in that "supposedly", not least because the show and the four main participants themselves are haunted by the shade of a real Ireland that will die, or is dying, or is dead.

Anticipate, perhaps, an inversion of the old woman's position: our ghosts inside and outside are not there, but we believe in them anyway, or might, or must.

John Kenny lectures in the English Department of NUI Galway and is currently writing a book about the work of Pat McCabe. The Revenant is at the Galway Arts Festival at the Druid Theatre, July 16-26. www.galwayartsfestival.com