“That would be an awfully small letter if they could,” she says while tempering the small smile the thought brings. If they were to ask the mice to go through the trouble of writing a letter, then they should not expect them to write on human scale.

Her search is halted briefly as the girl stops to watch Russell apply force on the grate with no visible movement from the metal. “I don’t think you have to break in. A couple of people I know at school always brag about getting in the tunnels when the tours aren’t going.”