The Potter's Field (The Chronicles of Brother Cadfael Book 17) - murder mysery set in an English medieval monastery
In this 17th novel in the series the abbey is granted the field where a potter used to live and work. That potter has renounced the world and left his wife to become a monk. But when the monks start ploughing the field a woman's body is revealed. Who was she and was she murdered?
I have read many novels in this series and most are very good. What I liked in this one was the historical backdrop and also the question why people would turn to religious life.
You can read all these novels separately but to understand the role of all the secondary returning characters like the ambitious prior and his sidekick but also the person of Cadfael himself you might want to start with book 1.