The year is 1242. Dominican inquisitors are traveling in France, persecuting and torturing suspected heretics. But then someone starts killing the Inquisitors....and whoever it is must be stopped before the fanatical Dominicans wreak their brutal revenge, provoking the people to rise in revolt against the French Crown for allowing the bloodshed. So the Crown sends Balian of Mallorca, a notorious alchemist/physician/polyglot who many believe to be a sorcerer, to Languedoc to solve the perplexing mystery. Along the way, Balian gains an unlikely partner in his investigations, a possibly clairvoyant noblewoman who disguises herself as a man...and they are plunged into a violent conspiracy of betrayal, deception, greed and lust that could cost them their lives...and spark a massacre.