Back to the 12th century again with wise, worldly herbalist Brother Cadfael of Shrewsbury's Benedictine monastery--who, called to a neighboring priory to nurse a visiting monk, finds the frozen body of Sister Hilaria, raped and murdered. And he soon learns that young Sister Hilaria was giving sanctuary to sturdy 13-year-old Yves Hugonins and his headstrong older sister Ermina--orphans of an aristocratic family, refugees in the latest civil war. (Their uncle, just back from a Crusade and unable, because of his allegiance to the wrong cause, to look for them in enemy territory, has sent his trusted, half-Moorish aide Olivier de Bretagne to the rescue.) Further events embroil Brother C. deeply in the fortunes of the Hugonins; his usual astute detective work unmasks the murderer; with old friend Hugh Beringar, he also succeeds in wiping out the band of savage marauders terrorizing the area. . . and makes a personal, euphoric discovery. Peters' reliable medieval performance as always--though the formula is starting to show slight signs of fatigue.