Meg Murphy is currently reading John The Revelator. The 17-year-old has already told her father, Peter, who wrote it, that she burst out laughing in a public place at the conversation between main character John and his Bible-referencing mother Lily. "It is the scene where he bleats 'Baaaaaaaa' at her and she says; 'You're fantasising about a sheep'," the author of the book laughs.

Sipping water in the upstairs bar of a Dublin hotel, the Byronic figure of Murphy cuts something of a dash. He is funny with it. He says his proud nose was inherited from his late father, Peadar, an All-Ireland Amateur Boxing Champion in the Fifties "who had a North American Native nose and eyebrow".

Before you know it, he is off and gone on to an- other tangent: rhapsodising breathlessly over books such as Davis Grubb's Night Of The Hunter, Ray Bradbury's Something Wicked This Way Comes, Russell Hoban's Riddley Walker, Jesus' Son by Denis Johnson or Tom Spanbauer's The Man Who Fell In Love With The Moon.

Murphy's debut novel -- a book he says his esteemed literary agent Marianne Gunne-O'Connor waited five years for him to deliver -- is being rhapsodised over as well, now. As none other than Colm Toibin says on the book's cover, "so original and disturbing and brave, it's an absolutely wonderful novel".

John The Revelator is a work of near genius. It is like a David Lynch movie set in Killinaskully. The story of a relationship between loner son John Devine and his mother, with whom he lives in a small town, it has echoes of Pat McCabe's The Butcher Boy.

Murphy's book title was inspired by seeing Blind Willie Johnson's 1927 song John the Revelator listed on an anthology of American music. The lyrics to the song -- whatever about the fact that St John wrote what would become the New Testament's White Album, The Book of Revelations -- could have been taken from Murphy's book:

"'What's John writin'? Ask the Revelator /A book of the seven seals!/Why me? thousands cried holy/Bound for some, Son of our God, Daughter of Zion, Judah the Lion/ He redeemeth, and bought us with his blood."

There are plenty of biblical references in Murphy's book. Asked how much of John Devine is Peter Murphy, he smiles sagely and says that he was "a watcher as a kid. The gospels are narrated by people who watch and bear witness to primary Jesus but also the other characters, and that's what John kind of does to a certain point in the narrative, whereby he begins to come into himself and his own body and enters the story.

"I suppose there's an element of that in any writing," he adds. "By dint of having to write the thing, you are every single character in it. You have to imagine yourself into every character, male and female; hermaphrodite, plant or animal. Even the landscape you have to put yourself. And the landscape is really important." From when he was a kid in Wexford, Peter Murphy liked to read stories that resonated with where he grew up in the country. "And it didn't matter," he says, "what part of the world the stories could have been set; they could have been in Nova Scotia or Alabama or the middle of Siberia." He remembers fellow Wexford writer Billy Roche's plays always being compared to Chekov.

"You know, it is just small towns," he says. "Universal small towns. But also, as I got older, I started to appreciate the beauty of language and a certain wildness of imagination ... " (Murphy's language and imagination is both beautiful and wild).

"As a kid, I loved science fiction and 2000AD comics," he says, adding that seeing movies such as Blade Runner and Videodrome in "the old flea pit down in Enniscorthy" when he was 14 had a big effect.

He has the cover design from his book tattooed on his left shoulder. His broody eyes twinkle with dark amusement at the thought of him one day looking like the tattooed psycho in Cape Fear played by Robert De Niro. Doubtless the 40-year-old will need to reserve more of his skin for future tattoos because prestigious Faber and Faber, who took up the book, obviously see a big future for the Wexford writer.

The day I met him, however, Murphy was drawn inexorably towards the past...

"The character of Lily in the book is based on a direct cross between my mother and my father. The figure of the mother you can't escape that, but her way of speaking and her sense of dry, hard-bitten humour is completely my father," he says. The youngest of five kids (the others are Philip, John, David and Imelda), Peter Murphy was the son of a post office clerk, Peadar, in Enniscorthy in Wexford. His dad, he says, was an extraordinary character -- "hyper intelligent, bitingly funny."

Peadar's passing in 2000 affected him profoundly. He doesn't believe John The Revelator would have been realised without his father on many levels -- most of them subconscious. "I would say one of the primary compulsions to write the book was to make sense of two dreams I had in the immediate passing that were so vivid and real that I woke up extraordinarily moved by having met him."

In one dream, he recalls Peadar told him that he was right to quit playing music in bands (he had been playing drums in raw bands such as The Tulips and Grasshopper for eight years) and to start writing seriously.

Peadar died on April 18, 2000 in Wexford County Hospital from a confluence of sickness and complications not helped by his lifelong heavy smoking. Murphy's youngest daughter (with Doodle Kennelly) Grace was born on April 26, "a week after the funeral."

Were you sad that your dad couldn't hang on to see Grace born?

"Yeah, there was that, but there was also a sense of them passing: one going out and one coming in."

The other main dream Peter had about his father was, he says, wordless. It was just Peadar's presence in a field somewhere. Whether the mind constructs a simulacrum of your loved-one out of its library of memories and sensations or whether you want to call it a visitation or a supernatural experience or an unconsciousness experience, he says, doesn't really matter so much as Peter found it a very comforting part of the experience.

"I was happy to see him again in whatever form," he says. "I still talk to him sometimes. I learn to recognise his presence in the form of memory rather than just go, 'Well, he's gone'." Peter doesn't think it makes any sense in terms of raw physics to consider all that energy or spirit can just be negated by death.

"It has to go somewhere," he says.

On the night that his father finally went somewhere, Peter remembers him as being quite alert; "his spirit was intact right until the end". At one point there were four other old men in the ward. One of the nurses came in and wheeled one of them out. "My father woke up or gained consciousness long enough to register this and he said, 'It's a four-horse race'. And then he slumped back into sleep. The last thing he said to me was, he asked me the time, and I was bizarrely grateful that I was wearing a watch."

And what time was it?

"It was 11.10pm, and he sorted of nodded when I told him. Those were the last words. If I hadn't been wearing a watch and I couldn't tell him the time," he laughs, "I would have felt terrible -- like I'd have failed him on his last request!" He says this with a wry chuckle.

Peadar, he adds, lost consciousness at midnight and died at around dawn. Peter started to write the book about a year after his father died -- he would get up at dawn every morning to write for two or three hours before his children woke up. He says he probably couldn't have written John The Revelator if his father were alive today. The book took about three or four years to write, but it was, he says, part of a process of about eight years of writing; "learning how to write fiction and making all the mistakes. You have to see how you are getting it wrong by actually doing it. I started seriously to sit down and try to do it in 2001."

In any event, the book is dedicated to Peadar and to his mother, Betty. His mother, ironically given the title of the book, is in St John's home in Enniscorthy where the aggressive form of dementia she has had for the past few years is being treated. A former telephonist in Gorey, Betty was an absolute artist with flowers. "She was forever walking. She came from a great family of walkers."

Peter's wife Doodle also comes from a great family. She is the only daughter of Brendan Kennelly, the wonderful poet and Trinity scholar. Peter met noted beauty Doodle "at a gig I was playing with The Tulips" in his early 20s.

He became a dad at 23 or 24, he says. "It took a while, just like the writing in fact. It took a while to subjugate the ego. It took a while to surrender and to learn how to act in service of somebody else and something else. It is not an easy thing to do in your 20s when you're all full of piss and beans."

He and Doodle have three daughters: Meg, 17, Hannah, 12, and Grace, eight. As a dad, Peter says he doesn't "like drama. I am not terribly strict but I don't tolerate any bad manners or notice. I love to talk to them. They teach me a lot. They taught me certainly how to write through the eyes of a child and then an adolescent. Then they taught me patience. Living with three girls is an incredibly civilising and healthy thing for me."

I wondered what it was like to be one half of a parenting team when the other half had been so public about her issues (manic depression, eating disorders and obsessive compulsive disorder); she wrote a series of brutally honest articles in the Sunday Independent's LIFE magazine about them.

There is a significant pause. "It is no joke being a parent," he says. "But the funny thing is what you think and what you want is not always the thing that is good for you. And in retrospect, can you figure how much good -- and I don't want to get into detail about this, other than to say that having the opportunity to parent them as closely as I could was for me particularly a f****** godsend, because if I was not as busy as I am I would go down in a hole. I don't think I am genetically prone to depression. But I think in my younger years, even when I was a teenager in bands on through to adjusting to fatherhood and trying to find work, the only bad periods I had was when I felt useless. So I like to be of use, in service."

Peter, who has been separated from Doodle since last year, lives in a semi-detached house in a little development about 15 minutes outside Enniscorthy, not far from the house in which he grew up. (Doodle has the kids in Blackrock in Dublin during the week and he takes them at the weekends.) "I am able to open the back door and let the kids ramble," he says.

"Our marriage was pretty much ended in 2003/2004 and we decided to remain in the same house and co-parent them. After a couple of years I rented a house in Deansgrange with a friend just to separate by increment," he says of the move home. "But I wanted to have a house for my kids and I couldn't afford to rent one in Dublin and the more I began to look up places that I could afford, the further I went. I began to realise that my family are in Wexford and in terms of work I could be up in Dublin in two hours. So I thought -- why not?"

In the book, Peter has one of his characters, James Corboy, say: "He still had feelings for her. OK, she wasn't the same woman she was 20 years ago, he wasn't blind. But when he looked in her face, she was still the same girl he married and danced with that day at the Salt Island Hotel. Even now, if she'd just make some gesture to let him know she was still interested, he'd respond in a second. He would, but she seemed to just not to care."

I can't help thinking that in that passage he is addressing Doodle.

"No, no," he laughs like Meg when she read the bit in the book about fantasising about sheep. "God, no. You go looking for biography in fiction at your peril. You will come up with some great, twisted, knotty roots."

You can't see why I would think that might be Doodle? "That could be a line pertaining to any experience I've had since I was 16. The book is a hall of mirrors, if you go looking for autobiography in it."

John the Revelator is published by Faber and Faber, €18.60.

- Barry Egan