Smoke In The Wind

Description for SMOKE IN THE WIND by Peter Tremayne:

Seventh-century Ireland is a ray of reason in a darkening world--and in this compelling mystery series, Sister Fidelma must frequently draw upon her own illuminating intelligence to shed light on the darkest of crimes....

While Fidelma and her companion Eadulf are journeying to visit the new Archbishop of Canterbury, their ship is blown badly off course, and the pair find themselves on the coast of modern Wales in the kingdom of Dyfed. There, hosted by the king himself, Fidelma is presented with her knottiest problem yet: An entire monastic community from the nearby countryside has disappeared without a trace.

While investigating this seeming impossibility, Fidelma and Eadulf are confronted with the apparently unrelated murder of a local girl--a death marked by more tragedy and consequence than anyone could have imagined....

This is #11 in A Mystery Of Ancient Ireland.