Out by Natsuo Kirino, trans. Stephen Snyder

Although unknown in this country, Natsuo Kirino is one of Japan's most successful crime writers. Out is the first of her novels to appear in English and it has to be said that the book is sui generis. It has been compared to Thelma and Louise, but the parallel is superficial, even if Kirino challenges assumptions about the submissiveness of Japanese women.

Four women work together on the night shift in a boxed-lunch factory. Each is dissatisfied with her life for one reason or another: marital discord, disappointing offspring, mounting debts, caring for a mother-in-law. The work is hard and the four have formed an alliance, making sure they get the least demanding tasks and looking out for each other on the midnight walk to the factory across an isolated industrial estate.

One night, Yayoi, the mother of two small children, discovers that her husband, Kenji, has blown their entire savings at a nightclub where he is infatuated with one of the hostesses. She loses control, strangles him with her belt and asks another of the women, Masako, for help. They bundle the body into the boot of Masako's car, take it to her house and enlist the help of the others to cut it into small pieces, which they then scatter in dustbins around the city.

Kirino's account of the dissection is clinical and detailed, although not much more so than post-mortems in Patricia Cornwell's novels. The big question is why the women do it, for it is one thing to share an uncongenial factory job, quite another to hack apart a human body. Kirino's answer, insofar as she offers one, is more disturbing than the actual event: they do not know what else to do, and are getting back at an unfair world. There is even a suggestion that the stultifying dullness of their lives has somehow anaesthetised them.

The novel is brilliantly constructed, powered by its own internal logic despite flaws in the plot. The proposition that a body could be shifted around as easily as this, defying the curiosity of neighbours and the suspicions of the police, is far-fetched. In that sense, Out is a melodrama, beautifully observed but always on the verge of detaching from reality.

This is, I think, because Kirino has set out to push her characters beyond normal limits. Having done that, anything could happen. She seems to enjoy the alternation between fear, exhilaration, jealousy and rivalry that follows the disposal of Kenji's corpse. The fracturing of the alliance between the women is presented realistically, although the novel takes a rather unconvincing turn when a loan shark stumbles on their secret and tries to blackmail them.

Probably the most unsettling thing in the book is the gradual development of a duel between Masako, the toughest of the four, and a nightclub owner who has been wrongly accused of Kenji's murder and wants revenge. There is a harshness in the earlier sections that some- times veers towards misogyny, but the nightclub owner, Satake, belongs in the dark recesses of a horror novel.

As the English title suggests, the series of events brings out something Satake and Masako have in common, as well as placing them far outside the law. In this skewed universe, it is no longer clear which is the predator and which the victim, leading to a denouement which is gory and predictable. It is also inhuman, making a connection between power and isolation that may prove too much for even the most sympathetic reader.

Joan Smith's 'Moralities' is published by Penguin