The news release for Eimear McBride's debut novel comes with a kind of caveat emptor, which warns the critic that the book is no conventional read. McBride's opening paragraph shows her starting as she means to go on: "For you. You'll soon. You'll give her name. In the stitches of her skin she'll wear your say. Mammy me? Yes you. Bounce the bed, I'd say. I'd say that's what you did. Then lay you down. They cut you round. Wait and hour and day."

Less patient readers may yield to their frustration and give up. Those who persevere will discover that while "A Girl Is a Half-formed Thing" is not an easy read in terms of subject matter and the way it is presented, its imposing stumbling blocks are its strengths. "Formidable," in both its meanings, best sums it up: This is a novel that initially intimidates, but after we have adapted to McBride's rhythms, its creative and emotional power renders us awe-struck.

The book concerns an unnamed Irish girl's fraught journey from birth to adolescence. Her brother, referred to throughout as "you," suffers from a life-threatening brain tumor. Her mother, designated "she," retreats into staunch Catholicism when her husband abandons the family. Our narrator grows up acclimatizing to the "empty spaces where fathers should be" and finds those gaps sporadically filled by a fearsome grandfather who wants to discipline her and a loathsome uncle who sexually assaults her. She progresses through her teens, in school and later in life, drained of self-respect and inured to disappointment and defilement.

McBride forces us to look on voyeuristically as her heroine, "full with marks of going wrong," spins out of control. It is a harsh and unsettling experience, intensified by the author's jerky, fragmented and syncopated prose. The syntax is chaotic. Sentences, largely comma-free, hit us as sharp shocks. Words collide, mutate and peter out as the girl's trauma reaches a crisis point. This is less a stream of consciousness than a sputtering trickle of half-formed thoughts and barely grasped impressions.

When faced with complex or genre-bending writing, critics love to draw parallels with James Joyce and Samuel Beckett. The majority of the time the connection is tenuous. Here it is fitting. Indeed, McBride has cited "Ulysses" as an influence. Her virtuoso style and ability to get inside a character — opening our minds in the process — is redolent of those past Irish masters. Unfortunately, such dexterity couldn't convince mainstream publishers: The novel lay rejected and unpublished for nine years until a tiny, plucky British publishing house took it on. It has been published in the United States by Coffee House Press.

McBride's book has been shortlisted for the Dylan Thomas Prize (to be announced in November), and in June it won the Bailey's Women's Prize for Fiction, beating the hot favorite, Donna Tartt's "The Goldfinch." "A Girl Is a Half-formed Thing" conveys far more in fewer words. This is brave, dizzying, risk-taking fiction of the highest order.

Malcolm Forbes has written for the Times Literary Supplement, the Economist and the Daily Beast. He lives in Edinburgh, Scotland.