A Virgin in the Ice — Ellis Peters

In the brutally cold winter of 1139, Brother Cadfael, amateur detective extraordinaire, is called to a neighboring priory to help a wounded traveler.

The sheriff instructs Cadfael to be on the lookout for a pair of orphans, a brother and sister, and their chaperone. They are somewhere in the snowy countryside-lost... or dead.

As dusk falls, Cadfael glimpses something glowing beneath the ice of a frozen brook: the body of a young girl. Sharp-witted and brave, Cadfael sets off in search of her killer. Before the first thaw, he will face more danger than many a monk sees in a lifetime.