I think I bought Absolution by Murder because the cover art was similar to Kate Sedley's early Roger the Chapman books (when they were available in the US without an amazon.co.uk account). It's followed me since 1994 or 1995, from New Jersey to Virginia and back home to Philadelphia, and it stood, pristine and unopened on my bookshelf until about a week ago. I've heard about Sister Fidelma in the intervening years but there was always something better to read.
I still feel that way. Absolution for Murder wasn't a bad novel, but I was underwhelmed. While part of a delegation to a convocation deciding whether the 7th Century Irish and English Churches will follow Rome or continue with their own calendars and traditions, Abbess Etian is murdered in her cell. Sister Fidelma, a highly qualified lawyer back home in Ireland, and Brother Edaulf, a Saxon monk/apothecary, use their complementary skills to solve the crime. Along the way, Peter Tremayne throws in some ecclesiastical history, four more deaths, and a bit too much exposition before unmasking the criminal I'd identified three pages after the discovery of Etian's corpse. I'll admit that I went into the book hoping that I'd put it in the donation box (I need the shelf space), but those lowered expectations may have upgraded my opinion by eliminating the specter of disappointment.