It tells the story of Rossamünd, a boy unfortunately christened with a girl's name, who has lived his entire life in a foundlingery (kind of an orphanage) before he is chosen to become a lamplighter in a far away city.
The book's action takes place entirely on the Half-Continent, a Dickensian world run by arcane science and alchemy, and plagued with deadly (and not-so-deadly) monsters.
The books are notable for the extraordinary amount of constructed language which pervades the entire narrative; an extensive glossary of terms is provided, as an in-universe document "The Explicarium".
Other examples include "Leers", individuals whose sensory organs have been specially treated with various alchemical concoctions to allow them to sense monsters or when another person is lying.
The darker students of habilistics are the black habilists or morbidists: the necrologists (those who raise corpses to life): the cadavarists (those who make monsters from parts, an illegal discipline called fabercadavery); the therospeusists (who grow monsters from living matter); or the transmogrifers ( the surgeons who operate on people to make lahzars, a process known as transmogrification).