ONE of Italy's most enduring mysteries, the disappearance of a Vatican schoolgirl 40 years ago, entered a new chapter when her brother met with a Vatican investigator whom Pope Francis has given free rein to get to the bottom of the case. Over the past four decades tombs have been opened, bones have been exhumed from forgotten grave sites and conspiracy theories have abounded in attempts to determine just what became of Emanuela Orlandi. The daughter of a Vatican usher whose family lived in the Vatican, Orlandi, then 15, failed to return home on June 22, 1983, following a music…