The House Gun by Nadine Gordimer Bloomsbury, pounds 15.99: Nadine Gordi mer's new novel explores a world of altered states and unconventional sex. Michele Roberts investigates
One myth of writing has it that creativity erupts only from personal damage and distress. So don't cut back your blooming neuroses; happy people can't make good books. A second myth holds that the best writing comes out of the struggle against injustice. Times of peace impose writer's block.

Nadine Gordimer provides a magnificent corrective to these narrow views. Having been active in the fight against apartheid in South Africa all her life, she shows in this gripping new novel how change engenders the need for understanding the human heart all over again. Gordimer has always been a novelist who refracts the political through the personal. Now she expresses the nation's shifts by adopting a new form, and uses the thriller to investigate how white liberals deal with altered power and unconventional sex.

From the beginning she leaves us in no doubt about what happened and whodunit. Carl Jespersen has been shot dead by his erstwhile friend Duncan Lindgard. The novelty lies in the inch by inch reckoning of the murderer's motives carried out by his traumatised parents, Harald and Claudia. Gordimer both exploits and reinvigorates the conventions of the thriller. While she allows the reader, with the suffering parents, to play reluctant detective, she also forces us to acknowledge, second by second, the agony of those forced to witness inexplicable violence.

The Lindgards' search for the truth brings them face to face with aspects of life they have previously managed to deny. The expert counsel they engage is black. Claudia, a doctor, and Harald, an insurance broker, have not met black people as equals before: "The Lindgards were not racist... Yet neither had joined movements, protested, marched in open display, spoken out". Motsamai Hamilton, the advocate, exhibits Mandelan tolerance and compassion to his anguished clients. Harald and Claudia, confronted with details of their son's private life, finally have their noses rubbed in what they had avoided: "There had been so much cruelty enacted in the name of that State they had lived in."

This is mainly a cerebral novel, concerned with the long trek towards morality, yet it is brought sensually alive by glimpses of the city landscape: the fortress-like townhouse where the Lindgards live; the cottage where Duncan and friends experiment with love; the colours of the market stalls; Hamilton's opulent house, formerly the property of white traders. Each place operates symbolically, indicating themes of entrapment and freedom.

The prison visiting room, a timeless place that cannot change, is finally replaced, in the thrilling denouement, by the courtroom. Courtroom dramas are a respected branch of thriller literature; Gordimer invigorates the genre by giving us the deep emotion that the protagonists struggle to repress. By now, we know what goes on below the surface.

Perhaps Duncan had a penchant towards violent solutions because of his personality formed in childhood; perhaps because he lived in a culture where people habitually killed each other. Whose fault is it that guns get left lying around on coffee tables?

At first the parents blame themselves. Then they blame Duncan's military service. They blame his permissive lifestyle. They blame apartheid. Finally, they allow Duncan to carry his own responsibility. The novel is so well written that it draws you into itself like a dream. I urge you to read it.