It began with Operation Sindoor. In the skies from Kashmir to Gujarat, Indians in blacked-out cities witnessed something extraordinary: roaring jets and drone swarms in a night sky lit up with streaks, flashes, tracers, and the arcs of missile exhausts?sirens and explosions puncturing the silence. Yet in radar rooms, missile batteries, and command bunkers, India?s air defence network was alive and alert, responding to incoming threats with speed, precision, and sometimes, terrifying certainty. This book takes you inside the invisible shield of Air Defence?what it is, how it works, and how it came to be. From loitering drones neutralised over Amritsar to missiles intercepted before reaching strategic sites, Operation Sindoor becomes the entry point into a larger, gripping story: the global evolution of air defence. It traces the legacy of the Patriot vs. Scud duels in the Gulf War, the drama and precision of Israel?s Iron Dome above Tel Aviv, and the tragic Balakot friendly fire incident that revealed the risks of a trigger too quick or a radar misread. Alongside these, it explores how India built its own multi-layered network?from legacy gun systems to S-400 missiles and AI-enabled coordination via IACCS. Rich with real-world incidents, human dilemmas, and the split-second decisions that define life and death, this is a primer not just on technology, but on the thinking that holds the sky. Because air defence isn't just about what launches. It's about what doesn't land.