Calling All Cahills

All the Cahills around the world have been summoned to Boston, Massachusetts, where Mr. McIntyre and the Cahill branch leaders await them. The only reason that all the Cahills would be called could only be the Vespers, a rival family that will stop at nothing to gather all 39 clues, even if it means murdering those they love. Can the Cahill family protect the 39 clues at all costs or will they lose all they've worked for?