The love-starved murderer Francie Brady, in Patrick McCabe's Booker-shortlisted novel The Butcher Boy, was the forerunner of a series of protagonists in McCabe's work to be torn apart by a dementia at once hilarious and heartbreaking. All of his books since then - The Dead School, Breakfast on Pluto, Mondo Desperado - are sustained by voices that are isolated and panic-stricken, absurdly funny because of their lack of self-awareness. In the end, the power of McCabe's work lies in the acute verbal facility of his protagonists.
Pat McNab, the matricidal character connecting the 13 stories in Emerald Germs of Ireland, is a McCabe archetype, a serial killer murdering the unfortunates who blunder into his house in unprepossessing Gullytown. In true horror style, they are viciously turned into fertiliser for his garden shrubbery. Pat's thoughts are dominated by music; each chapter is framed by the lyrics of popular ballads, the chorus reappearing in the next story. And his voice, mediated by an omniscient narrator, is by turns sly, gawky, innocent and wistful, but given to bursts of insane anger.
The recurring presence here is Pat's mammy, whose death at the hands of her son is established in the introduction. Each story is suffused by his struggle with his first victim: a woman whose own voice is alternately consoling and chiding. In fact, she has taken up permanent residence in Pat's imagination, exercising control as an accomplice to his grisly deeds.
In The Butcher Boy, the voice of the Blessed Virgin is described as being like all the softest women in the world mixed up in a huge baking bowl, and this is what maternal love represents for Pat McNab, too - when his mother is on form, that is. When she isn't, the love alliance he has formed with her to escape his brutal father leaves him unhinged. What became of Pat's father we never quite know: he is simply removed from their lives, either because he disappears or because he is murdered in his bed by Pat, although this may be one of his son's revenge fantasies.
The denial of love is at the centre of Pat's predicament. In one of the most affecting chapters in the book, "The Little Drummer Boy", about the loss of a Christmas toy that is Pat's only friend in the world, the narrator remarks: "He could never understand how the thing you loved could be taken from you."
McCabe's true fictional territory is the small Irish town, in which his main characters are caught in a blind pincer movement between a disastrous family and the unbearable perceptions imposed by the neighbours. There is nothing left but lonely, incommunicable fantasy, and this is always destined to turn malign.
Pat's fantasies underscore the novel's tone of hysterical banality. But it is perilous for an Irish writer to have his reputation rest on the mastery of language. Reviewers of McCabe's recent work have acclaimed his mastery of dialect and his lyricism, while bemoaning his use of familiar grotesqueries to create cartoon humour. But what they miss in McCabe is the deadly serious purpose behind the apparently relentless comic deployment of Hiberno-English. He is the laureate of shame.
Maurice Walsh is a BBC foreign correspondent