The Nightingale and Terho the Mouse-Lad (смешанная)

A story about the Nightingale - a gifted, power-hungry and malicious Unseelie shapeshifter - and Terho the mouse-lad, a chronically sick, lower class Seelie fae who only wanted to heal the sick. One was trapped in the underworlds as a punishment for his path of destruction, and the other was an innocent boy, determined to save what he thought was a wrongly caged bird.
This is the tale of how they both ended up bound to one another, changing the fae world they lived within - unfortunately, not for the good of all.