Rumours of plague threaten Cambridge again, ten years after the Black Death had almost laid waste to the town. Neither the church nor its priests had defended people from the disease and now they turn elsewhere for protection, to pagan ritual and magical potions. It is a ripe atmosphere to be exploited by the mysterious 'Sorcerer', an anonymous magician whose increasing influence seems certain to oust both civil and church leaders from power. One murder, another unexplained death, a font filled with blood, a desecreated grave - all bear the hallmarks of the Sorcerer's hand, only the identity of the magician remains a mystery. A mystery which Matthew Barthlomew must solve before he loses his reputation ... and his life.