Stopping to use a cash machine late one evening, a man inexplicably falls to the ground dead. Then a taxi driver is savagely attacked by two teenage girls. Quickly apprehended, they appal Inspector Wallander and his colleagues with their total lack of remorse. One girl escapes from custody and disappears. Soon afterwards a power failure causes an engineer to visit the malfunctioning sub-station, where he makes a grisly discovery. Wallander is sure that these events must be linked. His search for answers leads him perilously close to a shadowy group of anarchic terrorists hidden within the anonymity of cyberspace, and Wallander finds himself fighting to the bitter end to outsmart them.