As Mata and Ella run after the errant map, Mairan peeks down into the sewer, eventually getting down on hands and knees to look inside.
The scroll tube rests half in the muck, and half on the dry -- or at least merely damp -- lip of the sewer.
The sewers are relatively dark, although here and there, thin streams of light pour down from the holes in other manhole covers. From here, they can see intersecting tunnels with cryptic designations carved into the walls, matching the diagrams read over in the library.
Although it's a less than lovely environment, the sewers are navigable and, at least so far, safe.