RUSSELL Banks was feeling fragile. ''Late night,'' he said by way of explanation, raising his eyes towards heaven, mentioning Glasgow writers and a bar by the river. ''You could say it was something of a celebration, being back here. I like this place. And it's the end of a big stint. I've finished teaching. One way or another, I've been at it since 1970, but I've been at Princeton since 1982 and now I'm finished, so I'm celebrating.''

He was in Glasgow as part of a promotional tour for his new novel, Cloudsplitter, a hugely ambitious book which has recently appeared in this country, having been published to acclaim in America.

Cloudsplitter is the story of John Brown, the anti-slavery campaigner whose ''body lies a-moulding in his grave''. Narrated by Brown's son Owen, it is the story of a religious zealot and failed businessman who moved into history when he led a raid on the Federal arsenal at Harpers Ferry, Virginia, in 1859, hoping to provoke a slave rebellion. Most of his men were killed, including two of Brown's 20 children. No slaves rebelled and Brown was hanged. The cover shows Owen standing behind Brown's Mountain, surrounded by sheep and goats outside the small shack he built in Altadena, California, now part of a National Forest near Los Angeles.

''After Harpers Ferry, Owen was a wanted man. He went underground and popped up here. The early settlers in this community were obviously escaped slaves. Owen would have been aware of the routes used to smuggle slaves to freedom in Canada and California, and after Harpers Ferry would have been smuggled here himself.''

He is buried by the site of his cabin; the tombstone records his name and the dates of his life. ''Son of the Liberator'' it says. Time and again Owen questions his father's sanity, pondering the racial consequences if his father was insane. He also wonders why his father came to adopt his radical position.

Banks reckons most white Americans consider Brown was mad, ''but in a good cause''. And he neatly subverts the notion by adding a new dimension. ''If he was black, would we consider him insane? I don't think so. And what if he had succeeded? So much of Brown has to do with failure and guilt and our culture clearly links racism and failure.''

John Brown became a national icon after Harpers Creek. Victor Hugo, Emerson, Thoreau, and Melville all wrote about him, but he struck fire with the literary imagination following the publication of Steven Vincent Beret's novel John Brown's Body, which won the Pulitzer Prize in 1923.

Owen echoes the white liberal's dilemma. He says he is unable to identify with his own race's injustices and cruelties. He identifies with the oppressed, but he cannot take on their moral aura when he himself has not been persecuted. Which puts him in a place where many Banks characters have found themselves, a position of deracialised loneliness, where he is unable to identify with either race, where his natural allies are not those of his own class but others who feel marginalised, irrespective of their race or creed.

In a seminal section, Owen wonders why blacks trusted his father and concludes they trusted his rage. Owen, like his father, had lost his mother at the age of eight. Grief had marginalised him and the rage was a consequence of unresolved grief.

Which places Cloudsplitter with Banks's other books, such as Rule of the Bone, Affliction, and The Sweet Hereafter.

The break from teaching is also a break from fiction, but there's a screenplay to do and the libretto for an opera about his wife's great-grandfather, Joseph Twichell, Mark Twain's best friend and Charles Ives's father-in-law.