GRAHAM BRACK | Any comparison between Iain Pears' "An Instance of the Fingerpost" and Umberto Eco's 1983 classic "The Name of The Rose" is compelling, but unnecessary. Both are works of erudition, grand in scope, prepared to credit the reader with the intelligence and learning required to understand them, but also to furnish a little help when needed. Both are set in the past - Pears' book in the Oxford of 1663 - and both centre on a mystery; but neither could properly be termed a conventional whodunit. Even if we are bright enough to divine who may have murdered Pears' Dr. Robert Grove, we want to know why, and then we want answers to the questions that this in turn poses.

The format of the novel is easily explained, but complex in its working. We have, effectively, four novellas within one book, dealing with the same characters and hinging on the same sequence of events. Each narrator adds such information as he knows, and comments upon the facts as he sees them, interpreting others' actions and motives in the light of his own beliefs. We must accept that he may not be telling the truth, wilfully or otherwise, and that he may be - indeed, probably will be - varnishing his own part in the story.

Each has his own account of the truth, and each reads the evidence to back up his own version; but there is only one objective truth, and the reader is led on a search for this through the four subjective truths of the narrators. Events explained by one writer are seen differently by another. The facts which one can adduce demonstrate that another is in error, and the whole is set against a detailed background of seventeenth century Oxford. Whether it is accurate or not, I do not know; neither do I care, because it has the merit of consistency. I found myself putting the book down to think about the passages I had just read, constantly marvelling at the real life characters introduced by Pears, and reflecting that Oxford at that time had a galaxy of stars in all branches of learning. In an age when men could still hope to learn most of what was known about science and the arts in one lifetime, Oxford teemed with the gifted and the great, and several of them are here.

I dare not attempt to summarize the plot for fear of inadvertently giving away a clue and spoiling someone's enjoyment of a well-crafted, luxurious book. Pears has constructed a quartet of tales, each remarkable in itself and throwing light on some less-travelled byways of English history. How did the Commonwealth collapse in just two years after Oliver Cromwell died? Why did certain men escape any obvious punishment for their part in the Civil War? Who brought about the Restoration of Charles II?

A book of nearly seven hundred pages may seem like heavy going, but I assure you that the reward for tackling it is great. It flies past, and I am sure I am not alone in having sat up for an hour or two past my normal bedtime every night for a week, telling myself I would read "just a few more pages." So will you.