Two of Robert Harris' finest novels turned history on its head. His stellar debut, "Fatherland," revolved around the counterfactual scenario of Hitler winning the war. His more recent offering, "The Second Sleep," was an ingenious blend of dystopian future and medieval past. But with a few notable exceptions, the British author's novels have sourced their thrills from real historical events.

Sometimes he has woven a fictional story around documented facts (the attempts to avert war in "Munich," the eruption of Vesuvius in "Pompeii"); at other times, such as his retelling of the Dreyfus Affair in "An Officer and a Spy," he has clung more closely to the truth.

Harris' latest novel — his 15th — sees him once again re-creating a true story. He describes it as "the greatest manhunt of the seventeenth century." His fugitives are Edward Whalley and his son-in-law William Goffe, wanted for the murder of King Charles I. Their pursuer, and the novel's only invented character, is Richard Nayler, private secretary to the Lord Chancellor of England and "a shadow who causes things to happen."

"Act of Oblivion" could have been a dusty, distant, long-winded yarn. Instead, Harris delivers a gripping, well-paced tale rich in color, suspense and adventure.

It opens in the summer of 1660. Oliver Cromwell's Protectorate is no more. The Stuart monarchy has been restored, and the search is on to apprehend the traitors involved in the trial and execution of the last king 11 years ago. Nayler is tasked with locating the 13 renegades — or "regicides" — still at large. Most are rounded up in mainland Europe. But Whalley and Goffe have fled to America.

Nayler sets about finding the families of the men ("Love is their weak point"), then draws up a document advertising a considerable reward for the regicides' capture and dire punishment for anyone who harbors them. He then embarks on his assignment in earnest by boarding a ship and sailing from Old England to New.

Harris' narrative switches between hunter and hunted. Whalley and Goffe divide their time in hiding or on the move, and find their faith tested as they battle homesickness, harsh conditions and hostile encounters. "This is how we die," muses Whalley, "running from pillar to post, forced to put our trust in strangers, each one less known to us than the last."

Nayler endures his own ordeals and is regularly thrown off the scent by puritans who view his quarry as heroes. But he will stop at nothing to track down the condemned men, for his official mission is also a quest for personal revenge.

At various intervals, Harris flashes back to the English civil war and the last moments of a dethroned king. He serves up equally memorable depictions of plague, the Great Fire of London and a stormy voyage. But when he cuts back to the chase and charts the progress of three desperate men, he has his reader truly hooked.

Malcolm Forbes has written for the Times Literary Supplement, the Economist and the Wall Street Journal. He lives in Edinburgh, Scotland.

Act of Oblivion

By: Robert Harris.

Publisher: Harper, 480 pages, $28.99.