When Charles II came to the throne in 1660, he drew a line under the previous twenty years of civil strife in England. The ‘act of oblivion’ in the title of Robert Harris’s latest novel is in its most straightforward sense the Indemnity and Oblivion Act introduced by Charles’s government. The act granted pardons – with some exceptions – to anyone who committed crimes during the Civil War, or the Interregnum that spanned the years between the execution of Charles’s father, Charles I, in 1649 and Charles’s restoration. The biggest exception related to the ‘regicides’, the group of men who, in the words of their indictment, ‘did maliciously, treasonably and feloniously’ condemn the old king to death.

Several of the regicides escaped, either to the Continent or, in the case of Oliver Cromwell’s cousin Colonel Edward Whalley and Whalley’s son-in-law Colonel William Goffe, to America. Whalley and Goffe landed in Boston before attempting to disappear into an oblivion of their own. The English government made numerous attempts to find the fugitives, but they were sheltered by sympathetic Puritan colonists.

Harris dramatises this pursuit in typically brisk and confident fashion. His ‘Ned’ Whalley is pragmatic, wry and thoughtful. Whalley is a failed businessman whose life gains purpose when his cousin invites him to take up arms against the king. Goffe is more idealistic, a young Puritan preacher with