Combines thrilling stories of what it's like to be on the front line of Australia's first giga-fire with the hard truths of human-caused climate change, and what we do about it. Greg Mullins followed his father into fighting bushfires - it was in the blood. He fought major fires around Sydney and the Blue Mountains for decades, and studied bushfires in Europe, Canada and the US. He risked his life in the 1994 Sydney fires and, later, during our catastrophic Black Summer of 2019-20. As a career firefighter, he worked his way up the ranks to become Commissioner of one of the world's largest fire services, Fire and Rescue NSW, for nearly fourteen years. When it came to natural disasters there was little, if anything, he hadn't witnessed first-hand. Over five decades he watched as weather patterns and natural disaster risks changed, seeing bushfires becoming bigger, hotter and more destructive. He talked to scientists and weighed their evidence with his experience, coming to the realisation that man-made global warming was setting the stage for a deadly firestorm.