TO CALL Anne Enright the Pina Bausch of modern Irish writing would be no great exaggeration. Like Bausch, the pioneer of physical dance theatre, Enright's work is unflinchingly graphic, caustic, chaotic, funny, bleak, very loud and fiercely intelligent. The sheer muscularity of her prose can lift you off your feet, carry you into a crowded room and leave you standing in the corner or leaning against the kitchen sink, eavesdropping on every word. It needs to be approached with an open mind, and a fairly robust constitution.

The Gathering is Enright's fourth novel and sixth book. Set in the pre-Celtic Tiger Ireland of the later 1990s, it is a dark thriller-ish tale about knowing but not knowing, about memory and forgetting, a story of lives destroyed by secret sex and subsequent generations of denial, and about not being cherished enough as children of an over-large family.

Veronica Hegarty is 39 years old with a valedictory 2.1 in Arts from UCD, two young daughters, a big house, a decent enough high-earning husband with whom she no longer sleeps and no paid work outside the home. She stays up all night haunting the house, drinking a bottle of good Riesling or driving around looking for clues to the past in key places, in an effort to see clearly through the moil and roil and murk of memory and write down what did or did not happen there in that far off time, so that she can make sense of the awful thing that is happening in the present.

She and her family are waiting to get the body of her best friend and alcoholic brother Liam back from England so that they can wake him. He has been taken from the sea at Brighton Pier, his pockets full of stones and belly full of booze. He is wearing a high-viz yellow jacket over his shirt so that, thinks Veronica, they would find him before the sea rendered him unidentifiable and erased the details of his extraordinary beauty. The funeral of a suicide always attract a good crowd, observes Veronica wryly.

The Irish family has been entertaining us all since the beginning of time but not until the so-called Celtic Tiger have we seen so much written about the secret self. If you look at most novels or plays (Marina Carr comes to mind, as does Colm Toibin's The Blackwater Lightship) that have come out of CT Ireland, they turn out to be incredibly dark, as if all the razzmatazz is but a spin, a journalistic invention spurred on by those in power as an opium for the people, and that the secret self is only revealed in fiction.

Veronica and Liam belong to a rumbunctious, middle-class Catholic family of 12 full-term children (and seven miscarriages). "There were girls at school whose families grew to a robust five or six. . . and there were the pathetic ones like me, who had parents that were helpless to it and bred as naturally as they might shit" . . . a vivid if repugnant way of putting it. But then Enright relishes earthy descriptions of the body's natural functions, of excretions and secretions, smells and fluids, and of sex . . . good, bad and abusive.

Veronica spends the novel half-mad in a maelstrom of grief for Liam and longing for the tangible love of her sweet, vague and permanently tranquilised mother. She is frantic, gathering up memories, bits of facts, fragments of their fractured childhood, trying to piece together the events that led to Liam's death in England, and perhaps her mother's vagueness and her Uncle Brendan's madness and incarceration in a mental hospital.

Enright can be brilliant. She is good on the family and its pecking order and patterns (though I think she might have made the Hegarty clan a bit too big to bring them all convincingly to life) and her description of first arriving in London with Liam is absolutely spot on. She is also good at beginnings: "I would like to write down what happened in my grandmother's house the summer I was eight or nine, but I am not sure if it really did happen." Right away, Veronica is revealed as the classic unreliable narrator, and this gives everything that follows a nervy, unreal, skewed quality as seen through a distorting lens.

The weakest part of the novel comes early on, in a miscalculated scene set in the Belvedere Hotel in 1925, when we are introduced to the feisty Ada Merriman, Veronica's maternal grandmother, who might or might not be a servant or a prostitute, but who definitely was a theatrical seamstress. And we meet her future husband Charlie, and his acquaintance Lamb Nugent, an instantly repulsive Dickensian character who lusts after Ada, and who might or might not be the real villain of the piece.

Enright works Veronica hard and the reader too. The Gathering is both exhilarating and exhausting, a rollercoaster ride which is not easily forgotten.

We are compelled to look with Veronica through the distorting lens of memory into half-dark rooms and stuffy interiors, and what we see in them is not pleasant.

This is not a big novel. The story is quite slight, never building up to something more but chasing itself around, going over and over the same sparse facts and coming at them from different angles in an attempt to get at the truth, at what really happened to Liam . . . and perhaps his sweet mother and poor mad uncle before him . . . in the "good room" of Ada Merriman's rented redbrick house in Broadstone.