London in the spring of 1665 is a city full of fear. There is plague in the stews of St Giles, the Dutch fleet is preparing to invade, and a banking crisis threatens to leave Charles II's government with no means of paying for the nation's defence.
Amid the tension, Thomas Chaloner is ordered to investigate the murder of Dick Wheler, one of the few goldsmith-bankers to have survived the losses that have driven others to bankruptcy - or worse. At the same time, a French spy staggers across the city, carrying the plague from one parish to another.
Chaloner's foray into the world of the financiers who live in and around Cheapside quickly convinces him that they are just as great a threat as the Dutch, but their power and greed thwart him at every turn. Meanwhile, the plague continues to spread across the city, and the body count from the disease and from the fever of avarice starts to rise alarmingly . . .