Sacred Blood: The Vatican Assassin is a titillating tale of passion and intrigue that spans the centuries as the link between the confessional letters of an assassin to Popes Julius II and Leo X and a modern-day murder mystery gradually comes to light light unveiling the many layers of Rome's hidden secrets.

The intertwining story lines tell of historical researcher Anthony Hibbert, who is invited to Rome to study antique manuscripts at the Vatican Library Secret Archives, and Federigo Dottore, whose letters are stashed haphazardly within the records.

While working to...