Maurice Leitch, who stretched for the heavens with The Liberty Lad and Poor Lazarus in the Sixties, is still underrated despite the prizes that gloss his CV. Stuttering output - just seven novels, one book of stories and one novella in 33 years - is partly to blame. As is his lack of conspicuous frisson. His novels aren't sexy. Who wants to read the grim reaper of Northern Irish fiction?

Leitch's gothic imagination seems forever holed up in diehard, recalcitrant Ulster, a Protestant bastion ever hoarding the hurts of its history. In this wilderness lurch Leitch's misfit figures. The Smoke King views that world - as ever - through the eyes of the outsider. It marks a new boldness, a tight sharpening of vision, viewing that landscape, at the height of the Second World War, from three intersecting points.

For the Yanks are bedding down in Ulster - but not alone. The women aren't safe. The whiff of prejudice is rife. In the small market town near the edge of the lough, an American soldier, Willie Washington, is one of the gum-chewing black boys dispensing largesse in return for favours. Pearl is Willie's chosen dame; she's already a pariah, with her illegitimate children. Live now, pay later could be her epitaph, as around her death is hatching, not from the Luftwaffe above, but from closer quarters.

Pearl is not directly its victim. But death stalks Willie like some memory of the Klan. In drunken confusion, he is caught up one night in a murder, and with Pearl's help, hides away on an uninhabited island in the lough. At this point Leitch's writerly shrewdness is at its sharpest. He cuts away from - not towards - the chase. The drama that fascinates him, and which comes to devour the reader, is the struggle within the novel's benighted characters. In the quietest, most desperate way, it is Lawlor, the local policeman, in whom that turmoil is written deepest.

Lawlor, the third outsider, is a Catholic from the South. His pursuit of the fleeing soldier shifts the narrative, but here we see the object, not the subject of Leitch's tale. Its quarry is loss - and how to turn it on your fears, like a torch-beam of scrutiny. Pearl's 10-year-old son fears the loss of his mother's affection. Lawlor sorrows for the ghost of himself, as he was before his wife's death. Meanwhile, Willie is literally lost on an uncharted island, in foreign terrain.

As Leitch abandons the equilibrium of attention he gives his threesome - Pearl disappearing from the scene - you fear a loosening of grip. Then, in a stroke of singular brilliance at the book's last gasp, Leitch proves his mastery of plot. Pearl is horrifically resurrected, by the tenderest, subtlest of means. In that single stroke, we see that Leitch is cresting the apex of his powers. The Smoke King dares you not to inhale. Take it slowly; prolificity is overrated.