Castor appears to have build a fort of discarded books around herself, somewhere in a quiet, dark corner. To her credit, she seems to actively be trying to read from each one before they get added to The Walls, but she's not the best reader, and seems to actively grow frustrated with every book that isn't the one being sought.

Eventually she emerges, and sticks her face out into the aisles. "Any luck?" she stage-whispers to whoever is closest.