In the seventh century A.D., the murder of a high cleric threatens to result in war between two of Ireland's kingdoms. Sister Fidelma is summoned by the dying king to both solve the murder and prevent war. But Fidelma soon discovers that there are far more sinister forces at work than mere political intrigue.

In the 7th Century, King Oswy of Northumbria convenes a synod to hear debate between the Roman and Celtic churches. He has to decide which shall be granted primacy in his kingdom. When an abbess from the Celtic church is murdered, an investigation is launched by Sister Fidelma, Celtic, and Brother Eadfulf, Roman.

Sister Fidelma returns in the thirty-second Celtic mystery by Peter Tremayne. Ireland. AD 672. The Feast of Beltaine is approaching and the seven senior princes of the kingdom of Muman are gathering at Cashel to discuss King Colgu's policies. Just days before the council meets, Brother Conchobhar, the keeper of the sacred sword, is found murdered. Sister Fidelma and her brother Colgú fear that the killer had been trying to steal the sword that symbolises the King's authority to rule. And as rumours begin to spread of an attempt to overthrow Colgú, news reaches Cashel that a plague ship has landed at a nearby port, bringing the deadly pestilence to its shores. Amid fear and panic, Fidelma, Eadulf and Enda must work together to catch a killer as the death toll starts to mount . . .

Sister Fidelma needs to uncover the truth behind the murder of thirty-three young men that bear the marks of an ancient pagan death, while she tries to negotiate to build a Christian church in Druid territory.

In A.D. 670, an Irish merchant ship is attacked by a pirate vessel off the southern coast of the Breton peninsula. Merchad, the ship's captain, and Bressal, a prince from the Irish kingdom of Muman, are killed in cold blood after they have surrendered. Among the other passengers who manage to escape the slaughter are Fidelma of Cashel and her faithful companion, Brother Eadulf. Once safely ashore, Fidelma—sister to the King of Muman and an advocate of the Brehon law courts—is determined to bring the killers to justice, not only because her training demands it but also because one of the victims was her cousin. The only clue to the killer's identity is the symbol of the dove on the attacking ship's sails, a clue that leads her on a dangerous quest to confront the man known as The Dove of Death.

A perplexing case of murder and conspiracy in the pagan wilds of Northern Italy In 664 A.D., just after the events detailed in Shroud for the Archbishop, Fidelma of Cashel takes a unexpected detour on her trip home from Rome. While in the port at Genua (modern day Genoa), Fidelma—sister of one Ireland's kings and an advocate in her country's law courts—receives word that one of her old teachers, Brother Ruadan, is reaching the end of his days. Determined to see her old mentor one last time, Fidelma takes the treacherous journey to a remote abbey in the countryside—a place where the old pagan religion still has a hold and where even the Christians are often in bloody conflict with each other. But after she hears her dying teacher's last words, Fidelma's most dangerous adventure has just begun. With one murder after the next and a vicious war in the offing, it is up to Fidelma, alone and on her own, to unravel an extraordinary conspiracy before it is too late.

In 666 A.D., Fidelma of Cashel joins a group of pilgrims on a ship leaving Ireland for Spain. On the first night out, a pilgrim disappears, but was he washed overboard or murdered?

This is a collection of new essays on Peter Tremayne's Sister Fidelma novels, which feature Sister Fidelma's attempts to solve a wide range of crimes, often murders that occur under especially mysterious conditions. The novels, set mainly in 7th century Ireland, also include a great deal of history, which is not surprising given that the author is actually Peter Berresford Ellis, a noted Celtic historian. Some of the essays analyze aspects of the novels, focusing especially on the protagonist and her partner in detection and, ultimately, husband, Brother Eadulf. Other essays place Fidelma and the novels within the tradition of detective fiction. Still others explore the historical, intellectual, spiritual and geographical contexts for her labors. Also included are accounts of the author's career, the International Sister Fidelma Society, and the biennial Sister Fidelma conferences held in Cashel, Ireland.

Ireland, A.D. 671. An Anglo-Saxon delegation arrives in Cashel to debate the new religious rules that have been handed down from Rome. The Abbot of Imleach leads the Irish delegation, which is hostile to the new rules from outsiders. Among the Anglo-Saxon group is Brother Eadulf's own younger brother, Egric, whom Eadulf hasn't seen for many years. When the debate quickly becomes acrimonious, a local abbess has to step in as a mediator between the two sides. But not even a day later her body is discovered, bludgeoned to death. The Chief Brehon Aillín accuses young Egric of murder, and suspicions and tempers run high. With the war of words threatening to spill over into bloodshed, Fidelma is sure there is something more sinister behind the murder than religious differences, and she is resolved to find out what really happened-and why.

In January of 668 A.D., Fidelma of Cashel - sister to the king of Muman, an advocate of the Brehon law courts and a religieuse in the Celtic Church - is called to investigate the brutal murder of Abbess Faife and the mysterious disappearance of six young female religieuse accompanying her on a short pilgrimage away from her abbey. When Sister Fidelma and her husband, Brother Eadulf, arrive they find that there has been another death under mysterious circumstances, one of the senior scholars of the abbey has been bludgeoned to death. These two seemingly unrelated deaths - and the further mysteries of the trade ship lured to its doom on the rocky western shore of Ireland and the rumored figure of "The Master of Souls" wrecking havoc and raising rebellion - combine to create on the the most perplexing mysteries ever faced by the redoubtable Fidelma.