A distinguished scholar is murdered in his cell and manuscripts connected with his research are stolen. Fidelma and Eadulf are called to an abbey where intellectual disagreement, questions of doctrine and competition for rare texts have created an atmosphere of secrecy.
When the killer begins targeting those who pursue the missing writings, the investigation becomes a struggle to determine what the scholar had discovered and who feared its circulation. Personal strain between Fidelma and Eadulf further complicates a case in which religious scholarship is being used to conceal ambition and violence.