Medieval mystery and murder, travel and travail, in 1139 France—as a spunky, sensible, determined novice nun joins forces with a sculptor's apprentice to uncover some evil doings. It is the famous HÇloãse, abbess of the Convent of the Paraclete, the unrepentant if separated lover of Pierre AbÇlard, who enlists 18-year-old Catherine LeVendeur, daughter of wealthy merchant Hubert, to search out, in the library of the Abbey of Saint-Denis, a psalter prepared at the convent—a psalter that has been disgracefully altered to implicate fiery theologian AbÇlard (and HÇloãse) in heresy. Handsome, brawling Uncle Roger escorts the ``disgraced'' Catherine from the convent, but she does at last enter the unfinished church of the Abbey of Saint-Denis. But there, suddenly to her horror, ``a hugh black form came swooping down from the transept tower.'' The form is a very dead old sculptor, known and loved by Catherine and his apprentice Edgar, the mysterious Saxon. On the way to the killer(s) Catherine will confront: a miracle-working hermit, whose attributes send a parade of women to his hut; baffling sketches by the dead sculptor; a psalter decorated with fiendish devices; a pile of jewel boxes, and contracts with the devil. Two more murders will occur—as well as the discovery of some hidden relatives, consultations with AbÇlard, narrow escapes for both Catherine and Edgar, and a plod through the snows of Paris. It all ends with another swoop from a high place- -and second thoughts about the cloistered life. Gentle humor and a popping plot, with chapters graced by introductory commentary from long-ago saints and sojourners. Like the author's Guinevere trilogy (Guinevere Evermore, 1985, etc.), this offers a most likable heroine who wears well in the stretch.