December, 1380. When the corpse of Sir Robert Kilverby is discovered in a locked room, Brother Athelstan accompanies the King’s coronor to investigate. For the late Sir Robert had in his possession a sacred bloodstone which he was planning to donate to the Abbey of St Fulcher-on-Thames.

When Brother Anselm and his novice are summoned to the Church of St Michael’s in Candlewick to perform an exorcism, little are they prepared for the horror that waits. The demons and apparitions that plague the church would appear to have been summoned by an infamous sorcerer known as the Midnight Man. But what has he unwittingly unleashed - and why? Is someone using the haunting as the perfect cover for their murderous intent? And is there any link with the sudden disappearances of a number of young women in the area? The answers lie in the past and an unresolved wickedness from many decades before.

After his recent unveiling of a devious assassin, Sir Hugh Corbett has returned to service as the Keeper of the Secret Seal, begrudgingly admitting that his appetite for adventure has once again been whetted. Summoned to meet the King to be congratulated on their work together, Corbett and Ranulf learn of the death of Corbett's close friend, Ralph Grandison. Ralph, a leper, has been found dead in a rowing boat, a dagger thrust through his chest. But this murder is not the first of its kind.

Easter, 1177. Canterbury Cathedral, home to the tomb of martyr Saint Thomas Becket, bears the wounds of a terrible fire. Benedict, prior of the great church, leads its rebuilding. But horror interrupts the work. One of the stonemasons is found viciously murdered, the dead man’s face disfigured by a shocking wound. When the king’s clerk Aelred Barling and his assistant Hugo Stanton arrive on pilgrimage to the tomb, the prior orders them to investigate the unholy crime.

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 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.

Salisbury, 1226. A young pregnant woman is found tangled in reeds in the river Avon, her identity a mystery. Grieving widow Ela Longespée is determined to succeed her husband as sheriff of Salisbury, and quickly takes charge of the investigation. She soon finds herself in the thick of a neighborhood scandal and a struggle to maintain her authority. With multiple suspects, can she identify the true killer? 

It's 1194, and Sir Faucon de Ramis, the shire's newly appointed keeper of the pleas, must do his duty and make an official declaration of the cause of a miller's death. Saddled with a clerk who names Faucon his "penance", the shire's first crowner must thread the tangled relationships between the sheriff, the village of Priors Holston, and the priory that once ruled it. As a simple task takes a turn to the political, what seems obvious isn't, and what appears safe turns out to be more dangerous than he could imagine. 

Oxford, 1583. Giordano Bruno, a radical thinker fleeing the Inquisition, is sent undercover to Oxford to expose a Catholic conspiracy against Queen Elizabeth. But he has his own secret mission at the University, which must remain hidden at all costs. When a series of hideous murders are committed, Bruno is compelled to investigate. What he finds makes it brutally clear that the Tudor throne itself is at stake....

When the mutilated body of midwife and healer Agatha Kyteler is discovered in a hedge one frozen wintry morning, it seems at first that a lack of clues will render the crime impossible to solve. Then a frightened local youth inexplicably flees his village, and a hue and cry is raised in his wake. Sir Baldwin Furnshill, once a Knight Templar, has doubts about the boy's guilt. He enlists his friend Simon Puttock, bailiff of Lydford Castle, in the hunt for a murderer.

October, 1604. Former ship's surgeon turned country physician Gabriel Taverner is surprised to receive an urgent summons from his old naval captain. Now docked in Plymouth harbour, having recently returned from the Caribbean, Captain Colt believes his ship is haunted by an evil spirit and has asked Gabriel to investigate. Dismissive of the crew's wild talk of mysterious blue-skinned ghosts, Gabriel is convinced there must be a rational explanation behind the mass hallucinations.

As the leading churchmen and women gather at the Synod of Whitby in AD 664 to debate the rival merits of the Celtic and Roman Churches, tempers begin to fray. Conspirators plot an assassination, while mysterious, violent death stalks the shadowy cloisters of the Abbey of St Hilda. When the Abbess Etain, a leading speaker for the Celtic Church, is found murdered, suspicion inevitably rests on the Roman faction. Attending the Synod is Fidelma, of the community of St Brigid of Kildare.

It is the year of our Lord 1363. And in the cathedral city of York people are dying in mysterious circumstances. But there seems to be a common thread - the herbal remedies dispensed by Nicholas Wilton, Master Apothecary. The first victim is an anonymous pilgrim. But when a highborn nobleman dies after taking the same potion the authorities decide to act. Dispatched to York, in disguise, to unravel the mystery, Owen Archer, former Captain of Archers, apprentices himself to the Apothecary.

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.

After rising to prominence for his role investigating the case of Jack the Ripper, former Detective Inspector Daniel Wilson is now retired. Known for his intelligence, investigative skills, and most of all his discretion, he's often consulted when a case must be solved quickly and quietly. So when a body is found in the Egyptian collection of the Fitzwilliam Museum in Cambridge, Wilson is called in.