Thomas Chaloner, just returned from a clandestine excursion to Spain and Portugal on behalf of the Queen, finds London dank and grey under leaden skies. He finds many things changed, including the Government slapping a tax on printed newspapers. Handwritten news reports escape the duty, and the rivalry between the producers of the two conduits of news is the talk of the coffee houses with the battle to be first with any sort of intelligence escalating into violent rivalry. And it seems that a number of citizens who have eaten cucumbers have come to untimely deaths. It is such a death which Chaloner is despatched to investigate; that of a lawyer with links to 'the Butcher of Smithfield', a shady trader surrounded by a fearsome gang of thugs who terrorise the streets well beyond the confines of Smithfield market. Chaloner doesn't believe that either this death or the others are caused by a simple vegetable, but to prove his theory he has to untangle the devious means of how news is gathered and he has to put his personal safety aside as he tries to penetrate the rumour mill surrounding the Butcher of Smithfield and discover his real identity.
Gregory brilliantly evokes 1663 London in her brisk third mystery to feature spy Thomas Chaloner (after 2007's Blood on the Strand). On returning to England after a perilous mission on the Iberian peninsula, Chaloner finds himself out of favor with his mercurial employer, the earl of Clarendon, England's Lord Chancellor. He gets a chance to return to the earl's good graces if he can solve the peculiar death of Thomas Newburne, a solicitor and newsman who died after eating a cucumber. Chaloner soon learns that others have recently perished after a similar meal. His inquiries into the murky world of journalism and propaganda bring him into conflict with the Butcher of Smithfield, a shadowy thug and associate of Newburne's. Gregory salts the plot with several tantalizing subsidiary puzzles, and has impressively integrated into the story line not only historical figures but debates about the content of the period's newsletters and newsbooks.