Its the ultimate nightmare, imprisonment. But in the case of Zo Nielsen it was not just another bad dream: it happened. She was 10 when it all began, when she had the bad luck to fall within the gaze of Thurman Hayes, a man living out his own horror story. Set in the US, Ray Robinsons third novel draws on real events in a narrative of alarming power. Among the most impressive voices of Britains younger generation, Robinson is an uncompromising witness.

Each of the major characters in Forgetting Zoe is thoughtfully examined in turn. Their motivations are partially revealed; the rest is left to the reader, as Robinson is too skilled to offer easy judgments. It is interesting to see praise from Jim Crace included on the book jacket: one would have to look to Craces Being Dead (1999) to recall a British novel as convincing and as calmly aware of its own menace, its ambivalence. Also of note is that Robinson has achieved something that has consistently evaded British writers, with the possible exception of Jonathan Raban: he has evoked an authentic sense of the US, particularly in the sequences in the Arizona desert.

Thurman Hayes is more than a monster: he is a damaged psyche tormented by his fathers cruelty and his mothers dangerous passivity. Father scratched his weather-tanned neck. His grin was a challenge . . . Thurman was almost fifteen years old and claimed to have an upset stomach. Father said that if he was staying at home then he had to help him out on the ranch, you choose. When Father looked into the rhyme of Thurmans face it was obvious he hated what he saw: his own weaknesses, his failings.

The boy is numb, wrung dry and emotionally paralysed by his fathers presence. On discovering the girlie magazines that his father has kept hidden, the boy gazes at them. But no matter how long he stared at the images, he failed to feel a thing. The boy has begun to sleepwalk through life, or so it seems, merely watching.

From the outset Robinson imposes Thurmans disconnected personality on the narrative. Equally compelling is the elegantly cryptic prose, complete word pictures emerging from single sentences: The slam of the front door; the sound of Fathers pickup revving: tires. (This is interesting: a British writer, having set his novel in the US, is using US spelling.) For Thurman the sight of his fathers hands only ever spoke one word and that word was hurt.

One could almost begin to feel sorry for Thurman, the only child of aging parents. He speaks in an old-fashioned, mannerly way; he seems diffident. But the evil is there, seething away in the form of all the slights he has ever suffered.

Meanwhile, across the continent, on Unnr Island, in northern Canada, an imaginative little girl is searching for happiness. Zo is another child who has never had it easy. Her mother lives in a state of self-absorption. Ingrid. Never Mom or Mommy. Within a short sentence Robinson reveals volumes about the relationship between the mother and daughter. When Zo goes missing Ingrid begins to look for her. The search of the cottage leads Ingrid into every possible hiding place. The silence of the house never seemed so loud.

Eventually the mother checks the childs room. She stood looking at the straw crosses above Zos headboard, to protect her from the trolls, the men of the Underworld. Her unmade bed of ruffled pink sheets. Moppy, her stuffed bunny, and the drawings on the walls. Had Ingrid ever spent this long in her daughters room just looking?

No trace of the child is found. There are no clues. Ingrid continues to search, Zos body in her mind, bobbing in slow sea-time. People run out of sympathy; they talk about her behind her back: Theres that Ingrid Nielsen. She still thinks her daughters alive. The childs father, Jon, a Norwegian sailor with whom Ingrid had a brief romance years before, returns to help find the child. But he leaves, and being alone proves too much for Ingrid.

Robinson has written a thriller: he summons the menace, the devices, the details, the way pieces fit. Above all he looks to the way in which people respond, and how they forget, once the novelty wears off and they return to their own lives. The public as much as the criminal is on trial here, albeit a detached, non-judgmental trial. Robinson is studying the jailer and the captive; Thurman is trapped by his own madness. The real tragedy is how the ordeal shapes and distorts Zo. For her the torment becomes the familiar; ultimately she needs Thurman.

For Zo survival settles into an ongoing game of cat and mouse; the characterisation of Thurman is precise and unsettling. The brutality is shocking, yet subtle such is Robinsons eerie compassion. He sustains the pace and the psychological intensity, as well as, most importantly, the ambivalence. The older, now-grown Zo retreats into anonymity, behind a shield of abrasive asides, deliberate weight gain and tracksuits. Freedom becomes another ordeal.

A strange little episode near the end of the novel says, as do so many of Robinsons elliptic observations, so much. Zo, having admitted that her life was also ended when her captor died, is staying at a hotel. A birdcage is hanging in the courtyard. She opens the door to the cage. Go on. Fly. Be free. But the bird just sits there.

Eileen Battersby is Literary Correspondent of The Irish Times