Matthew Bartholomew, unorthodox but effective physician to Michaelhouse college in medieval Cambridge, is as worried as anyone about the pestilence that is ravaging Europe and seems to be approaching England. But he is distracted by the sudden and inexplicable death of the Master of Michaelhouse - a death the University authorities do not want investigated.

harles II is well established at White Hall Palace, his mistress at hand in rooms over the Holbein bridge, the heads of some of the regicides on public display. London seethes with new energy, freed from the strictures of the protectorate, but many of its inhabitants have lost their livelihoods. One is Thomas Chaloner, a reluctant spy for the feared secretary of state, John Thurloe, and now returned from Holland in desperate need of employment. 

Hugh of Singleton, fourth son of a minor knight, has been educated as a clerk, usually a prelude to taking holy orders. However, feeling no certain calling despite a lively faith, he turns to the profession of surgeon, training in Paris and then hanging out his sign in Oxford. A local lord asks him to track the killer of a young woman whose bones have been found in the castle cesspit. She is identified as the impetuous missing daughter of a local blacksmith, and her young man, whom she had provoked very publicly, is in due course arrested and sentenced at the Oxford assizes.

In the sapping summer heat of 1665, there is little celebration in London of the naval victory at the Battle of Lowestoft. The King, his retinue and anyone with sufficient means has fled the plague-ridden city, its half-deserted streets echoing the sound of bells tolling the mounting number of deaths. Those who remain clutch doubtful potions to ward off the relentless disease and dart nervously past shuttered buildings, watchful for the thieves who risk their lives to plunder what has been left behind.

December 1940. With the Luftwaffe pounding the city nightly, Londoners seek refuge in underground stations. Aldwych has been taken out of service to provide shelter for the British Museum's priceless Elgin Marbles, as well as civilians escaping the bombing. When the body of a young man is discovered on the tracks, wearing evening dress but barefoot, Detective Chief Inspector Coburg and Sergeant Lampson are on the case. Before long, more bodies are discovered, and Coburg's wife Rosa becomes a target for the brutal killer.