Of Sun & Moon (Midnight Guardian Series, Book 1‪)‬

Over the years, humans have pieced together sighting and assumptions to create the myth of the tooth fairy. As it turns out, they were pretty much wrong.

Keira Ryan has the same worries as any other high school freshman...her classes are boring, she's crushing on an older guy, her best friend is dating a spoiled cheerleader...and, oh yeah, she's a tooth fairy destined to bring about the end of a royal line of vicious, blood-sucking tyrants.