A paper map of the Reaver castle's earlier layout that Doctor Bones produces to fix Louis's location.
As Juice Box prepared to go in, Doctor Bones turned suddenly serious and announced he had a previous map of the place. The skeleton DJ pulled out a paper map of The Reaver Castle, and Carl used Find Crawler to point out where Louis was — in an area of line cubicles, which if the configuration matched would mean a room no bigger than a coffin. Carl then touched the spot where Samantha waited on the other side of the wall.
With that, Juice Box said she'd signal when she had him and went invisible.
A folded paper map of the castle's interior drawn from an earlier configuration of its shifting corridors.
The reference that turned Carl's magical location hit into an actionable floor plan.