Old Diary is a book found in Dishonored 2.
[The pages have been half-eaten by rats, only a few are still legible]
4th, Earth, 1837
Fools. Running in the streets. No worse place to be! Everyone knows plague is carried on the winds. I will do the only sensible thing and lock myself up until the infected breezes move on. I have plenty of dried meats, and other foodstuffs. Enough to last me quite a while I think. Empress Jessamine called for calm, and I will heed her call, alone!
25th, Nets or thereabouts
Strong winds tonight. I am afraid for anyone who hasn't barricaded themselves inside as I have. I know that Empress Jessamine and her Royal Protector, Lord Attano, will find a solution soon.
High Cold, Probably
I have lost track of time. Sometimes I sleep for days. I might be sick. But I dare not venture out to find a doctor. An ill wind might find me. And the plague is far worse than melancholy, is it not?
Month of Clans, I think.
The wheat tastes rancid. Still no word from the Empress or Parliament. No City Watch walking the streets and ringing bells to announce a cure. But I know Empress Jessamine will do everything in her power to save Dunwall from the plague. I need only wait a little while longer.
The book can be found in the boarded-up apartment during the mission A Long Day in Dunwall.