Paul David, computer expert and ingenious hacker, is caught in the electronic meshes of a international data network and is confronted with criminals operating behind the scenes of a worldwide organization, which uses the most modern communication technology for cleverly coordinated, criminal actions. Then Paul is suspected of double murder. When desperately trying to escape the noose he is surrounded by more and more people who obviously have the same aim in common: to catch him in a lethal trap. Only Dettmar Mushaake, expert for computer crime from the regional police department, seems to be on Paul's side - and, of course, Diddle, a mongrel who is anything but a lapdog. He tracks down ambushes, delivers messages and leads Paul's pursuers astray.