Second sister - Ho-Kei Chan

Gossip. Rumour. Revenge.
Wun Wah Tower. Kwun Tong district, Hong Kong.

When Siu-Man jumped from her window on the twenty-second floor, everyone assumed it was suicide. But Sui-Man's sister, Nga-Yee, a quiet and unassuming librarian, is determined to prove it was murder. The police aren't interested in re-opening a solved case so she contacts a man known only as N. - a hacker, and an expert in cybersecurity and manipulating human behaviour.

What follows is a cat-and-mouse game through the vibrant city of Hong Kong. The pair's investigation takes them from creepy commuter-train gropers to Siu-Man's gossipy friends to the dark corners of the city's digital underground - where online bullies, sexual predators and shady tech businesses stalk their prey...
Reviews for Second Sister:
'An elaborate plot' New York Times

'Moves at a breathtaking pace and, with its bounty of high-tech hazard, excites like a vintage Tom Clancy novel' Wall Street Journal

'An important, multidimensional and even educational read into the dangers of cyber bullying' The Straits Times

'Sharp-witted and intense... Dangerous feuds, cybertheft, and a predator stalking Hong Kong' Booklist