While performing in the theatrical and religious festival of Corpus Christi Day in Coventry, Joliffe is summoned by Bishop Beaufort to use his skills as a spy to uncover the mysteries of the town's elite. A merchant has gone missing, presumed dead-and members of Joliffe's company are implicated in the crime. To uncover the truth, Joliffe must unravel the devilish machinations of a secret sect of heretics bent on destroying the Church.