In the secret archives of the Vatican, a monk is brutally murdered. He sacrificed his life for the diary of an unknown alchemist who was burned at the stake by the Inquisition. However, his legacy promises impending doom, as bizarre assassinations suddenly occur in the Eternal City. Once a symbol of wealth, gold now transforms into an unpredictable weapon that claims more and more lives. At the request of an old school friend of Mycroft Holmes, Oscar Wilde travels to Rome disguised as a priest to put an end to the deadly events.