The Demon and the City (The Detective Inspector Chen Novels)

In this “satisfyingly suspenseful” urban fantasy, a demon teams up with a human detective on the Singapore police force (Booklist).

Zhu Irzh is having trouble adjusting to life on Earth. The food is bland, the colors dim, and the weather much too chilly for a demon used to the balmy climate of the underworld. Recently attached to the Singapore Three police department, Zhu Irzh has been assigned to help humans like Detective Inspector Chen investigate cases that overlap this world and the world to come. But how dedicated can a demon be to justice when his last assignment was to Hell’s vice squad—whose job is not to prevent vice, but to promote it?
Zhu Irzh is pondering these philosophical questions when he catches his first murder case: the savage killing of a rich would-be witch outside of the occult market. Chen is on a well-deserved vacation, so the demon takes charge himself, unearthing a supernatural conspiracy that proves Hell holds no monopoly on evil.
The Demon and the City is the second of the five Detective Inspector Chen Novels, which also include Snake Agent and Precious Dragon.