The Elixir Black Market is a book found in Dishonored.
[Excerpt from a letter]
We've seen widespread looting since the Month of Clans.
It wasn't prevalent at first, but it's a pattern now: There's an outbreak in one of the districts and the Watch moves in. We quarantine buildings, put down weepers, and deport anyone showing early signs. Afterward, the Dead Counters come through and the lawyers write up the paperwork to transfer ownership of businesses and homes at Parliament's discretion. Soon after, like clockwork, the gangs begin tearing the place apart.
There's a fairly robust black market now, because everyone wants elixir and most can't afford it. Even Sokolov's brand won't help you if you've already got the plague, but getting a regular dose is your best chance if you want to avoid contracting it.
Some of the gangs have taken to buying small amounts and watering it down before selling it. And I have to admit, if I didn't have an officer's ration, I'd be buying from them.
City Watch, Third Regiment