Isis, otherwise The Blessed Very Reverend Gaia-Marie Isis Saraswati Minerva Mirza Whit of Luskentyre, Beloved Elect of God III, is the teenage granddaughter and spiritual heir of Salvador Whit, patriarch of the Luskentyrians. They are a religious cult who live in a commune in Stirlingshire, and reject most technology. They run their lives according to a collection of beliefs and rituals which were 'revealed' to Salvador when he was washed ashore on one of the Western Isles, and 'married' two young Asian ladies. Haggis pakora is thus a staple of the cult's cuisine.
The novel opens shortly before the Luskentyrian Festival of Love, held every four years, about nine months before every leap year day (February 29). Those born on that day are believed to have special power. This includes Isis herself, Elect of God, due to take over leadership of the cult.
The heart of the novel is Isis' voyage into the world of 'the Unsaved' (who are also known as 'the Obtuse', 'the Wretched', 'the Bland' and 'the Asleep'), through southern England looking for Morag, who is feared to have rejected the cult.
Because of Isis' anti-technology and self-denying puritanical beliefs, she has to use a Sitting Board (a hard board she can put over the comfortable seats in cars in order to deprive herself of cushioning). She also uses the technique of Back-Bussing in order to avoid paying for a ticket on the bus. This consists of getting on buses, and when the conductor comes along, asking for a ticket in the opposite direction while looking confused. This normally results in being allowed to get off at the next stop and pointed in the right direction.
While searching for her cousin, Isis meets Rastas, policemen, white power skinheads, and other dubious characters of a sort she has never encountered before, and tells the story of the cult and the rationale behind its rules. Isis’ maternal grandmother, Yolanda, a feisty Texan woman, appears and lends her support to Isis' quest. Isis' friend Sophi, although she is not part of the cult, is very close to her. She meets her whenever she goes to her house to use the Luskentyrian method of free (if laborious) telephone communication, using coded rings.
When Isis finds Morag, she learns that though Morag has lapsed somewhat in her Luskentyrian beliefs (her work as a porn actress is not inconsistent with the cult's beliefs) she had every intention of returning for the festival. The story now takes a more sinister turn, as we learn that the now supposed motive for Isis' journey was cooked up by her brother in an attempt to get her out of the picture in a bid to take over the leadership of the cult.
Isis also learns the history of her grandfather, and rescues her grandmother from an old people's home. Confident that her mild senility will recover once she is in a less boring environment, Isis soon learns more of the origins of the cult from her. She finds out that her grandfather was a robber on the run, and that the cult he set up is based on lies.
Returning with her grandmother, enhanced maturity and a lot more information, Isis must decide what to tell the other members of the cult.
The cult is dealt with very sympathetically, especially coming just after the Waco Siege in 1993; Banks ensures the theology that Isis believes fervently in at the start of the book, is coherently and cleverly put together, even as events cause her to start to doubt.
Banks has called it:
'a book about religion and culture written by a dedicated evangelical atheist - I thought I was very kind to them...Essentially, Isis makes the recognition that the value of the Luskentyrian cult is in their community values rather than their religious ones. She recognises that efficiency isn't everything, that people not profit are what matters.'