Gumshoe Zoom: Alchemy

From publisher blurb: Chemistry or magic? Madness or miracles? Poison or power? Blend all those elements — and more — with Alchemy, the latest Zoom in on a historical magic system for GUMSHOE gaming. Operating at every level from the base dungeon-crawl to the Awakened Working, this magic system gives you the secrets of matter — and maybe a touch of mercury poisoning.