I'm home recovering from hospitalization for an intestinal problem (all solved). I downloaded a freeware brainstorming software called Brainstorm Lite for Mac (at http://mac.sofotex.com,
which also has PC freeware and shareware). So I sat down this afternoon and did some brainstorming and actually made quite a bit of progress! I will continue to plan.
It has to do with contagious diseases in the Ottoman Empire in the mid-19th century, specifically with an outbreak of cholera that devastated the capital city of Istanbul in about a week's time.