AD 848. Bernwyn of Lythe, the young daughter of an ealdorman, spurns marriage and chooses to remain a virgin dedicated to Christ. When she is found murdered in the chapel where she kept her nightly vigils, it is thought that she has fallen victim to the Viking raiders who are ravaging the country and the butterflies found resting on her body are taken to be a sign from God. But what if Bernwyn was not all she seemed? Could the saintly deeds attributed to her have been carried out by someone else and the people have set up a shrine to a false virgin?