The Scales rulebook contains everything needed to start a campaign.
The book starts with the rules system, including Gestalt and character creation, occupations and hobbies, action resolution and combat. The game system is designed to be simple and fast, with emphasis on the narrative side of roleplaying rather than straight simulation of actions.
The rest of the book describes the game universe in depth, with chapters about magic, magical beings, technomancers (alchemists who cast spells by using mana drawn from the organs of magical beings), Masks (arts performed by dragons to conceal their use of mana), and a description of the different factions of the game (the thirteen families and three generations of Dragons, awakened magical beings, Technomancers, the Celestial Dragon and his offsprings the Newborns...)
The book ends with a scenario ("keening"), designed to introduce players to their Gestalt.