February 1574 and London is in a fervour of paranoia, superstition and rumour. Mob violence is commonplace. A whispered word is all it takes to condemn a woman to burn as a witch.
Having foiled the 'Incendium' plot against the Queen, intelligencer Dr Christopher Radcliff's standing within court is high. However, he has no time to reap any reward. Counterfeit coins bearing the likeness of his master, Robert Dudley, Earl of Leicester, are circulating on London's streets. This in itself is a treasonous offence, but now slogans have begun to appear on walls and doorways, implying that Leicester harbours treacherous intent.
So Radcliff and his team of informants and amateur spies are sent out into the city's markets, drinking dens and brothels to track down who might be behind such outrageous and subversive acts. It will take them down a murderous path in pursuit of an elusive foe with an extraordinary agenda. And time is running out: for when rumour and fear catch fire, then surely violent insurrection and bloody chaos will follow . . .