In 1350 the people of Cambridge are struggling to overcome the effects of the Black Death - and with a high mortality rate among priests and monks, the townsfolk are vulnerable to sinister cults that have sprung up. At Michaelhouse, Matthew Bartholomew is training new physicians when the body of a friar is found in the massive chest that the university uses to store precious documents. While investigating, Bartholomew stumbles across a derelict church being used as a meeting place for the mysterious sect he believes is at the heart of a web of blackmail.

The fourth chronicle of Matthew Bartholomew continues the adventures of the 14th-century Cambridge physician when he is called to attend to two deaths from some poisoned wine. The opening of a new and very well-endowed college has created petty infighting amongst the academics as new appointments are made. The winter and spring have been appallingly wet, there is a fever outbreak amongst the poorer townspeople and the country is not yet fully recovered from the aftermath of the plague.

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.

Matthew Bartholomew, doctor of medicine and fellow of Michaelhouse, Cambridge, is travelling with a party from the college to accept the gift of the living of a parish in Suffolk. One of his companions, Unwin, an unworldly scholar, is to be installed as priest. Their journey is not without incident - they are chased by footpads, pass through an eerie village abandoned after the recent plague and find a man barely alive on a gibbet - so they reach their destination with some relief. But their thoughts of recovering while enjoying the local Pentecostal Fair are soon curtailed.

Michaelhouse is in uproar: Kenyngham, the saintly but ageing master, has announced his retirement, and with unseemly haste Runham arranges his own 'election' as his successor. Within days he has dismissed several members of staff, including the redoubtable laundress Agatha, and is making life so unpleasant for the scholars that even Matthew Bartholomew believes his future as physician and teacher at the college is untenable.

Cambridge, 1354. Christmas approaches, and the town is gripped by the worst blizzards in living memory. As the physician Matthew Bartholomew struggles to help the poorer citizens cope with freezing temperatures, his colleagues prepare for the festivities. The weather has trapped many travellers in the town, including Matthew's erstwhile love, Philippa. She and her wealthy husband are invited to Michaelhouse for the main feast, and Matthew is horrified that he does not immediately recognise the overweight, sulky woman who once stole his heart.

In Cambridge, 1355, the colleges of the fledgling university are as much at odds with each other as they are with the ordinary townfolk. This tension has recently been heightened by the return of two well-born murderers after receiving the King's pardon, showing no remorse but ready to confront those who helped convict them. And in the midst of this Bartholomew the physician is called to the local mill to examine two corpses. It is almost a relief to be able to turn his back on the fractious town, but as always in Cambridge nothing is disconnected.

February 1355: Oxford explodes in one of the most serious riots of its history. Fearing for their lives, the scholars flee, and some choose the University at Cambridge as their temporary refuge. But they don't remain safe for long. Within hours of their arrival, the first of their number dies, followed quickly by a second. When Matthew Bartholomew begins to investigate the deaths, he uncovers evidence that the Oxford riot was not a case of random violence, but part of a carefully orchestrated plot.

Cambridge University is in dire financial straits: the town's landlords are demanding an extortionate rent rise for the students' hostels, and the plague years have left the colleges with scant resources. Tension between town and gown is at boiling point and soon explodes into violence and death. Into this maelstrom comes a charismatic physician whose healing methods owe more to magic than medicine, but his success threatens Matthew Bartholomew's professional reputation - and his life....

It is not long before they learn that the friary in which they are staying is not the safe haven they imagine - one guest has already been murdered. It soon emerges that the dead man was holding the Hugh Chalice, a Lincoln relic with a curiously bloody history. Bartholomew and Michael are soon drawn into a web of murder, lies and suspicion in a city where neither knows who can be trusted.

Rumours of plague threaten Cambridge again, 10 years after the Black Death had almost laid waste to the town. Neither the church nor its priests had defended people from the disease, and now they turn elsewhere for protection, to pagan ritual and magical potions. It is a ripe atmosphere to be exploited by the mysterious 'Sorcerer', an anonymous magician whose increasing influence seems certain to oust both civil and church leaders from power.

When a wealthy benefactor is found dead in Michaelhouse, Brother Michael and Matthew Bartholomew must find the culprit before the college is accused of foul play. At the same time, Cambridge is plagued by a mystery thief who is targeting rich pilgrims. Moreover, pranksters are at large in the university, staging a series of practical jokes that are growing increasingly dangerous and that are dividing scholars into bitterly opposed factions.

There is something very amiss in the finances of Michaelhouse. Despite a new influx of well-heeled students, there is an acute lack of funds for the upkeep of the buildings, even for decent provisions. It is only when the brother in charge of the account books dies unexpectedly that some sort of explanation is revealed: he has been paying large amounts of money for goods the college itself has never received.

In 1358, over a century after its foundation in Cambridge, the college of Michael House is facing a serious shortfall of funds and competition from upstarts rivals such as Zachary Hostel. Their problems are made no easier by the hostility of the town's inhabitants, who favour the university moving away to the Fens. This simmering tension threatens to break into violence when a well-known tradesman is found dead in one of the colleges.

In 1360 Edward III issues a call to arms, as sporadic attacks by the French threaten to turn into a full-blown invasion. In Cambridge, fear of the enemy is magnified by the belief that foreign agents are lurking in the area. Tension runs ever higher as rumours and ignorance fan the flames of suspicion amid preparations for war. And then the first murder occurs - of a French scholar living in the town.