Bound By Stardust by Angela J. Ford

A stardust collector. A handsome immortal. And a floating kingdom full of sinister secrets.

Once a year, on All Hallows Eve, stardust falls from the floating kingdom. But only one person is brave enough to enter the boneyard and gather the magical powder: Asira, the Stardust Collector.
Known as a sharp-tongued spinster with a talent for healing, Asira leads a lonely life in the woods. However, inside the boneyard, Asira finds more than just stardust.
Lying among the dust is a wounded man, one of the immortal Masters who dwells in the starry kingdom above. She takes him home, hoping for a magical gift that will change her humble life.
The man, Drazhan, is handsome, flirtatious, and has a unique way of getting under her skin. Full of gratitude, he vows to change her life, but only after he enacts his revenge on those who cast him down.
A week later, during the annual tithe, Asira becomes one of the Chosen—those elected to live in the floating kingdom and serve the Masters.
But all is not as it seems.

Beneath the glamor and gold, a sinister secret is waiting to reveal itself. Asira will need her wits, Drazhan’s help and stardust to unravel the dark secrets of the floating kingdom.