Showing When Red is Black by Xiaolong Qiu

When Inspector Chen Cao agrees to do a translation job for a Triad-connected businessman he is given a laptop, a 'little secretary' to provide for his every need, medical care for his mother. There are, it seems, no strings attached . . . Then a murder is reported: Chen is loath to shorten his working holiday, so Sergeant Yu is forced to take charge of the investigation. The victim, a middle-aged teacher, has been found dead in her tiny room in a converted multi-family house. Only a neighbour could have committed the crime, but there is no motive. It is only when Chen returns and starts to investigate the past that he finds answers. But by then he has troubles of his own.