Хеннинг Манкелль - Firewall

Ystad, Sweden. A man stops at an ATM during his evening walk and inexplicably falls dead to the ground.
Two teenage girls brutally murder a taxi driver. They are quickly apprehended, shocking local policemen with their complete lack of remorse. One girl escapes police custody and disappears without a trace.
A few days later a blackout cuts power to a large swath of the country. When a serviceman arrives at the malfunctioning power substation, he makes a grisly discovery.
Inspector Kurt Wallander knows these events must be linked, but he has to figure out how and why. His endeavors are made all the more difficult when he discovers personal and professional betrayals within his own team. Lonely and frustrated, he begins to doubt the worth of continuing his work as a detective.
The search for answers eventually leads Wallander dangerously close to a shadowy group of anarchic terrorists, hidden by the anonymity of cyberspace. Somehow, these criminals always seem to know the police’s next move. How can a small group of detectives unravel a plot designed to wreak havoc on a worldwide scale? And will they solve the riddle in time?