1217: The war for the throne of England is far from over but as Edwin Weaver waits to see where his lord's loyalties lie, a messenger arrives from Roche Abbey: one of the monks has been murdered. The abbot needs help to find the killer, and Edwin soon find himself within the unfamiliar and claustrophobic confines of the abbey, where a killer walks unnoticed among his brothers. Drawn ever deeper into a web of lies and deceit, Edwin not only has to discover the identity of the murderer, but must also decide where his real duty lies.