From the Publisher:
The year is 1663, and the setting is Oxford, England, during the height of Restoration political intrigue. When Dr. Robert Grove is found dead in his Oxford room, hands clenched and face frozen in a rictus of pain, all the signs point to poison. Rashomon-like, the narrative circles around Grove's murder as four different characters give their version of events: Marco da Cola, a visiting Italian physician - or so he would like the reader to believe; Jack Prestcott, the son of a traitor who fled the country to avoid execution; Dr. John Wallis, a mathematician and cryptographer with a predilection for conspiracy theories; and Anthony Wood, a mild-mannered Oxford antiquarian whose tale proves to be the book's "instance of the fingerpost".
Iain Pears: An Instance of the Fingerpost. Prime Crime, ISBN: 0425167720 (March, 1999), 735 p., $7.99