Nebula Dragons are nocturnal creatures. With the best eyesight to be found, they are often seen staring into space. Each dragon tends to observe a particular nebula and will eventually change their colors and patterns to match it. As the nebula changes over time, the dragon changes with it. The more intricate the design of the nebula, the better chance an individual has of attracting a mate. It is said that the markings on no two Nebula Dragons will be exactly the same.

Dragons are highly-intelligent reptilian creatures that—from a human perspective, at least—appear to live forever. Many different varieties of dragon exist, each with their own unique qualities, habitats, and behavior. Adolescence in dragons is usually marked by the growth of a hatchling’s wings, although not all breeds of dragons grow wings and some breeds have other traits that indicate the beginning of maturation. In Galsreim, dragons and humans coexist peacefully.

Thousands of years ago, according to the legends of the Firewind and Fallensnow clans, dragons with the stars reflected in their wings came to the Valley of Teeth to calm rampant chaos. They stayed for a while, sewing the seeds of morality and justice. Then, inexplicably, they departed, promising that one day they would return. No one knows who they really were or where they came from, but they are known to the Valley clans as Keepers of the Stars.

Beiyiru is a descendant of these Keepers. Feisty and opinionated, she disapproves of the residents' corruption and decadence. She tries to convince her fellow Keepers that it is time to return, time to teach the Valley dragons once more how they should live. Some of them agree, but many, including her friend, Serreia, insist that they still remember their old lessons and will find their own way to restore prosperity.