In May 1195, Sir John de Wolfe is summoned to inspect a corpse in Exeter’s cathedral precinct. Aaron of Salisbury, a Jewish money-lender, has been found dead, his head enveloped in a brown leather money bag, a scrap of folded parchment clutched in his hand. On it is written “And Jesus went into the temple and overthrew the tables of the money-changers.” This is just the beginning of a strange series of murders in which an apt biblical text is left at the scene of the crime. Setting out to track down a literate and Bible-learned killer in an age when only one percent of the population can read or write, Sir John deduces that he is looking for a homicidal priest.