In the powerful new thriller from the author of the international bestseller The Last Templar, a geneticist and a CIA agent on a deadly quest to find the most dangerous book in the world discover a secret that has destroyed everyone in its path for centuries.

Naples, 1750. In the dead of night, three men with swords burst into the palazzo of a marquis. Their leader, the Prince of San Severo, accuses the marquis of being an imposter, and demands to know a secret only the marquis harbors. In the fight that ensues, the false marquis escapes over the rooftops of Naples, leaving behind a burning palazzo and a raging prince now obsessed with finding his quarry at any cost.

Baghdad, 2003. An army unit on a routine mission makes a horrifying discovery: a state- of-the-art, concealed lab where dozens—men, women, children—have died, the subjects of gruesome experiments. The mysterious scientist they were after, a man believed to be working on a bioweapon and known only as the hakeem—the doctor—escapes, taking with him the startling truth about his work. A puzzling clue is left behind: a circular symbol of a snake feeding on its own tail.