England may have survived the Armada threat of 1588, but when Spanish galleys land troops in Cornwall on a lightning raid seven years later, is it a dry-run for a new invasion? Revenge for the sacking of Spanish shipping and ports? A warning shot to Drake and Hawkins? Or is there, perhaps, a more sinister motive? The Queen is speechless with rage at Spain's temerity. Sir Robert Cecil demands answers. But as John Shakespeare tries to get a grip on events, England's secret defences begin to unravel as one by one his network of spies is horribly murdered. But what has all this to do with Thomasyn Jade, a girl driven to the edge of madness by the foul rituals of exorcism? And what is the link to a group of priests held prisoner in the bleak confines of Wisbech Castle? From the pain-wracked torture rooms of the Inquisition in Seville to the marshy wastes of fenland, from the wild coasts of Cornwall to the sweat and sawdust of the Elizabethan playhouses, and from the condemned cell at Newgate to the devilish stench of brimstone and fear as demons are driven out by unspeakable means, THE HERETICS builds to a terrifying climax that threatens the life of the Queen herself.