It is 3.07am and a production line has stopped. Is it a fault, a hack, or both? The operator can't restart it and the screens show a communications fault. They ring the on call engineer, who thinks it looks like a network problem. The engineer rings IT, who point out that the plant network isn't theirs, they only look after the office. Nobody is being unreasonable. Nobody has a current drawing of what is connected to what. Half an hour in, nobody can say whether this is a fau