The Demon and the City: The Detective Inspector Chen Novels, Book Two

When Chen goes on holiday, his demonic partner Zhu Irzh finds himself alone in Singapore Three. The missing body of a brutally murdered socialite and the strange experiments of a well-connected, beautiful, young heiress leads Zhu into a maze of death and corruption. Chen returns to the city just as Zhu's baser instincts seem to be getting the better of him. While the rest of the police department thinks the worst of Zhu, Chen suspects something more malignant, particularly when the forces of Heaven begin manifesting themselves in Singapore Three, taking sides and leaving a trail of death and destruction in their wake.