"Lingua Franca" (Rated G, H/W), February 2019 Holmes Minor Monthly Prompt

[gardnerhill]

Title: Lingua Franca
Author: gardnerhill
Form/Wordcount: 221b
Characters/Pairings: Sherlock Holmes/John Watson, my "Oubliette" series
Rating: G
Warnings/Content: None
Summary: Watson learns that there are all sorts of codes useful in a blind and blinkered country. A story in my Oubliette series.
Author’s Notes: For the Holmes Minor February 2019 prompt: Mother Tongues

( Story below the cut. )