In the church graveyard, they find a strange tombstone: no name, no date, and the Lucian crest.
At the base of a tombstone, a small arrow points down into the earth, which can only mean one thing. It's time for everyone's favorite cemetery pastime: grave-digging.
Nellie and the kids dig into the grave and find another entrance to the vast Catacombs of Paris.
Deep inside, they find a vase and a mural depicting the four original members of the four branches of the Cahill family.
They open the vase and find a vial of liquid wrapped in paper. Amy takes the paper, and they look at the vial. It has a strange message on it. It's an anagram, which Amy unscrambles: "As thou charge this, so I charge thee. Use thy skills the truth to free" (17.86).
Before they even have time to think about it, Jonah Wizard jumps in to take the clue.