Start with the trunk.
Every story and number in this book is a branch off four ideas. Hold these, and the details have somewhere to hang.
Water runs on small computers in places nobody visits.
Wells, pump stations, towers, and lift stations each have a controller, a screen, and a link back to the plant.
Remote access built a road from the internet to the pump.
Exposed screens, factory passwords, and vendor links left doors open, with a few busy operators to watch them.
Water has no undo button.
Shut down the wrong thing and you cause the outage the attacker wanted. Every fix has to be narrow.
Done means two checks pass.
The door is closed. The pump still answers the operator, and the alarm still sounds.
How the book follows them. Chapters 1 to 4 show the first two ideas. Chapters 5 and 6 show where the third one bites. Chapters 7 to 9 show the method that delivers the fourth, and what it's worth.