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.