EVERY IMAGINATIVE writer exhibits a case of arrested development, fixated on some stage in time, some crucial event, around which the rest of his imaginative life loops and circles, straying from the source but always returning to it, attempting to absorb it, to comprehend it, finally to transcend it (which may not make him so different from you and me).

Like most such simple reductive generalizations, such flatly unequivocal propositions, like this one could be endlessly qualified and would certainly be denied - and yet . . . .Take Ian McEwan, a young writer of real talent if I ever read one, whose material is as banal and bizarre as sex and death, whose dreams are circumscribed by his parents' loss, his sister's love. The Cement Garden is his first novel and second book. Three years ago he published an extraordinary collection of short stories, First Love, Last Rites , unique variations on the same common themes.

The themes may be commonplace but McEwan's handling of them is not. He tells the story through a 14-year-old boy, Jack, who lives, at the beginning, with his barely middle-class parents, two sisters, Julie 16 and Sue 12, and a six-year-old brother in a bleak urban landscape that is, in fact, London, but could as well be Chicago. McEwan has a compelling narrative gift, and The Cement Garden is a riveting novel from its opening paragraph:

"I did not kill my father, but I sometimes felt I had helped him on his way. And but for the fact that it coincided with a landmark in my own physical growth, his death seemed insignificant compared to what followed. My sisters and I talked about him the week after he died, and Sue certainly cried when the ambulance men tucked him up in a bright red blanket and carried him away. He was a frail, irascible, obsessive man with yellowish hands and face. I am only including the little story of his death to explain how my sisters and I came to have such a large quantity of cement at our disposal."

How the cement came to be disposed of is the hinge on which the plot turns. It was purchased - 15 bags of it - because Jack's ailing father intended to pave over the garden he was no longer well enough to care for, "to surround the house, front and back, with an even plane of concrete." Jack and his father begin the job, but as Jack lingers in the cellar pondering the astonishing new mystery of sex, his father collapses in the wet cement. "The radio was playing in the kitchen. I went back outside after the ambulance had left to look at our path. I did not have a thought in my head as I picked up the plank and carefully smoothed away his impression in the soft , fresh concrete."

So much for father. And so much, eventually, for mother, who fades away in her upstairs bedroom shortly after Jack's 15th birthday, leaving the children in conceal her death in order to prevent the dissolution of their family, which, flawed as it is, is nonetheless all they have." "If we tell them, 'I began again, 'they'll come and put us into care, into an orphanage or something. They might try and get Tom adopted.' I paused. Sue was horrified.

"'They can't do that,' she said.

"'The house will stand empty,' I went on, 'people will break in, there'll be nothing left.'

"'But if we don't tell anyone,' said Sue, and gestured vaguely toward the house, 'what do we do then?'"

What they do then, during their summer of freedom, is to retain the established structure but change the established roles, parodying the previous familiar model. Jack becomes the sometimes irascible father, Julie the mother who mercilessly babies Tom, the youngest, as if he were a doll, clothing him in wigs and dresses, moving him backwards from bed to crib, protecting him with a fierce, childlike and terrible devotion. Sue giggles with her older sister, and comments on them all in her diary.

To reveal more of the plot which McEwan so skillfully unfolds, planting seeds in the first few pages that he harvests at the end, would be to assume his task and to diminish the reader's pleasure, because in this book you first want to find out what happens next. The Cement Garden possesses the suspense and the chilling impact of Lord of the Flies but without the philosophy lessons. Its cool, matter-of-fact depiction of child and adosescent sexuality gives it the truth but not the zaniness (nor the psychiatric sessions) of Portnoy's Complaint . Its characters are sympathetic, its tone sustained but muted, and its style spare and unadorned, quietly rendering the narrator's sense of the fragility, the impermanence and the mysteriousness of the world.

As one might expect, the flowers that grow from the cracks in a cement garden are ugly - we have to grant a writer his obsessions - but The Cement Garden itself is original, memorable, powerful and right. Fortunately too, it is short, because I could not put it down.