During their ride, Tiberinus and Rhea point out landmarks and how they have changed. They arrive at a marble building, and Tiberinus explains that Annabeth must descend underground to “[f]ind the altar of the foreign god” (293). When Annabeth asks if any of her siblings have found the Mark, Tiberinus admits that none have. Rhea notes Annabeth’s bravery, which may indicate greater strength. Rhea and Tiberinus depart, and Annabeth descends.

Thinking back on the adventures of her childhood, she hopes she has not been led into a trap and steels herself to move forward. The Mark burns in the middle of the door she pushes through. She finds herself in a basement filled with storage crates. In a corner, she notices an opening that drops into a cavern where she sees the Mark burning, and ponders how to descend safely, with intelligence her only “special power” (297). Using items she finds in the crates, she creates a rope ladder and climbs down to the cavern.

She lands in a shallow canal and worries briefly that it could be part of Daedalus’s labyrinth. She ties a piece of string to her rope ladder to stay connected to it and follows the burning Mark as it appears.