Firewall

I've just returned from nine weeks overseas and only finished one book, Firewall by Henning Mankel, which I very much enjoyed.  There are mysterious people dying suddenly or being murdered and Inspector Wallender must find the connection as he battles with his colleagues and superiors.  Throughout the story, Wallender "consults" his former mentor, Rydberg (now dead) - "What would Rydberg do?"  When he finally learns the truth, he must act quickly to avert disaster.  The story makes you think about the world's vulnerability and dependency on computers.