Robyn was an average girl in everything but name. She got average grades, had a few friends, and the only hobby she had was watching television. She had always expected her life to stay relatively the same.
At least until she felt an odd tugging of her... soul? Yeah, you could call it her soul. It went on for days, and when she went to follow, she found herself trekking through deep woods far beyond the lights of the city.
Beneath the ground, a society of shape-shifters exists and thrives. They built up their world, tiny as they were. At their Academy they train teenagers from each root of the tree they live under, and when they graduate, they are put into work, often shifting into the forms of sparrows to do their duties.
You see, these tiny people only turn into one thing: a sparrow. That is their curse, set upon them long ago, before the ships came and a town was built around them, resulting in a few human visitors.
The only people different from the sparrows are the crows and the owls. The crows help defend the tree from humans, and though there were once many, only one remains to do his duties.