Joe

Joe is a janitor who works in the main train station in Chicago. Dresden got to see Joe on a regular basis while travelling and working for the Paranet.

He might be a character of interest based on the author's comments in his 2014 Reddit AMA.

"Is Joe the janitor at the train station in Small Favor actually just a janitor, or is he, like Uriel, an angel in disguise?"

"No comment."