The Raven in the Foregate — Ellis Peters

When the beloved Father Adam dies, Abbot Radulfus recommends the young priest Ailnoth for the parish of Holy Cross, known as the Foregate. Ailnoth has much to recommend him, but his zeal and lack of pity quickly alienate him from his flock. So much so that no one is truly sorry when his body is discovered in the millpond on Christmas morning.

Brother Cadfael, herbalist monk and amateur sleuth, fears murder, and because of Father Ailnoth's unholy zeal, the malefactor could he almost anyone. Worse yet, one of the prime suspects is Cadfael's friend Benet, a young man who arrived with Father Ailnoth and went right to work eagerly helping the monk in his Herbarium. With partisans of the dispossessed Empress Maud believed to he in the area, Cadfael wishes that his assistant's identity was not so clearly another piece of the mystery....