ISIS Whit is not your average 19-year-old. She has, since her leap-year birth, been destined as the Elect of God to lead the Luskentyrian religious sect when its founder, her grandfather Salvador, dies.
The Luskentyrians live in a ramshackle estate near Stirling in central Scotland. Like many such groups, they are suspicious of the outside world and its inhabitants, the Unsaved, and prefer to lead a simple, self-sufficient and meditative existence.
Modern conveniences such as electricity, televisions, CD players and telephones are frowned upon. Isis only leaves the community once a week, to play the organ at a church in Dunblane.
Every leap year, the Luskentyrians hold a Festival of Love, where copulation is encouraged in the hope that one of the issues of these casual couplings, will be born on February 29 and therefore be the next generation's Elect of God.
The forthcoming festival's guest of honour is to be Isis' cousin Morag, who is supposedly pursuing a successful career as a classical musician in London.
However, preparations are thrown into disarray, when Morag writes to say she will never return to the commune and wishes to remain with the Unsaved.
Isis is chosen to travel south and find out what has happened.
An inner tyre tube is adapted into a boat which she navigates down the River Forth to Edinburgh. She then hitches a free ride on an empty train bound for London where she learns the awful truth about Morag's new vocation.
Britain in the 1990s is seen through the eyes of guileless Isis. She responds to fascist thugs, vicious guard dogs and porn parlour bouncers, with the same candour. But she is no pushover.
Her canny American grandmother Yolanda has taught her self-defence, and she is accomplished at hitting out at those who threaten her.
Isis wanders through this strange, fractured landscape of post-industrial Britain, like ET with an attitude.
Her bizarre encounters are described by Iain Banks with his customary humour. He has a strong affection for the more unorthodox members of British society.
With his perfect ear for the vernacular his dialogue is fresh and often very funny.
Whit is not Banks' best work and despite its length at 450 pages, is a fairly insubstantial novel. In an attempt to make the mystical sect authentic, he describes in detail its weird beliefs and chequered history and this is often tedious.
However, there is enough in the novel to make it enjoyable and Banks is, as ever, an astute observer of a country in crisis.