Firewall by Henning Mankell

Stopping to get money from a cash machine one evening, a man inexplicably falls to the ground: dead. A taxi driver is brutally murdered by two teenage girls. Quickly apprehended they appall local policemen with their total lack of remorse. One girl escapes police custody and disappears without a trace. Soon afterward a blackout covers half the country. When an engineer arrives at the malfunctioning power station, he makes a grisly discovery. Inspector Kurt Wallander is sure that these events must be linked - somehow. Hampered by the discovery of betrayals in his own team, lonely and frustrated, Wallander begins to lose conviction in his role as a detective. The search for answers leads Wallander dangerously close to a shadowy group of anarchic terrorists, hidden within the anonymity of cyberspace. Somehow these criminals seem always to know the police's next move. Wallander finds himself fighting to outsmart them In their gripping police procedural about our increasing vulnerability in the modern digitalized world.