Darker by Four

Rui has trained her magic for years toward a single purpose: to avenge her mother's death. Yiran is the black sheep of a powerful family, because he was born with no magic at all. Nikai is a Reaper in the service of the Fourth King of Hell.

When the king vanishes, the underworld begins to crumble. If he is not found, the collapse will reach the human world. Around the same time, an accident passes Rui's power to Yiran. Rui loses the only tool she had for her revenge, and Yiran feels for the first time that he belongs somewhere.

Then Rui learns she may be the one person able to locate the missing death god. To get her power back, she makes a dangerous bargain with another King of Hell, and the deal's terms put more at risk than her own plans.

This is a fantasy about exorcists, grief and the cost of power, built on Chinese diaspora folklore. The story moves between three viewpoints: a vengeful young woman, an outsider handed what he never had, and a Reaper whose master is gone. It is the first book of a duology.