For the first time in decades The Eternal City is paralysed by a blizzard. And a gruesome discovery is made in the Pantheon - one of Rome's most ancient and revered architectural treasures. Covered by softly falling snow is the body of a young woman - her back horribly mutilated . . . But before Costa, Peroni and Rome's Questura can begin a formal investigation the US Embassy has brought in its own people, FBI Agents who want the case closed down as quickly and discreetly as possible.

But Costa is determined to find out why - and as the FBI grudgingly admits that this corpse is not the first, the mutilations of the woman's body point to Leonardo Da Vinci's Vitruvian Man - and to a conspiracy so sinister and buried so deep, that only two people know its true, crazed meaning.