''A fictional tour de force which combines erudition with mystery'' PD James

Oxford in the 1660s. Sarah Blundy stands accused of the murder of Robert Grove, a fellow of New College.

Four witnesses describe the events surrounding his death: Marco da Cola, a Venetian Catholic intent on claiming credit for the invention of blood transfusion; Jack Prescott, the son of a supposed traitor to the Royalist cause, determined to vindicate his father; John Wallis, chief cryptographer to both Cromwell and Charles II, a mathematician, theologian and master spy; and Anthony Wood, the famous Oxford antiquary.

Each one tells their version of what happened but only one reveals the extraordinary truth. Brilliantly written and utterly convincing, An Instance of the Fingerpost is gripping from the first page to the last.

''A novel that combines the simple pleasures of Agatha Christie with the intellectual subtlety of Umberto Eco, don''t let it pass by unread.'' The Times