The Holy Thief
by Ellis Peters. This is the nineteenth installment of the Brother Cadfael mystery series.
In this story, the relics of St. Winifred disappear after being put in safe keeping during a flood. When they are discovered, and a man having some information about the theft is found dead, Cadfael must solve the crimes and exonerate the young man who seemed to have motive but no alibi.
This was another entertaining story which has an interesting juridical procedure for determining the intentions of St. Winifred with respect to the final resting place of her relics.