This book tells the fascinating story of William John MacKay, a man who dominated policing in New South Wales for three decades, until his death in 1948. MacKay was fearless, brilliant and ruthless. He was responsible for beating-up striking unionists, but he also smashed the semi-fascist New Guard when it was a threat to democracy. He reformed and modernized the New South Wales Police Force, and he framed innocent men for capital crimes. He cracked down on organized crime and corruption, and he was himself corrupt. Dogged by scandal, he was the subject of no fewer than seven royal commissions. The story of W.J. MacKay is also the story of policing in Australia, from the 1920s through to the corruption-riddled period after the Second World War. This gripping history explores the messy complexities of police power and sheds new light on a fascinating period in Australian police history Richard Evans is Honorary Fellow in the School of Humanities and Social Sciences at Deakin University, Australia. His previous books include Do Police Need Guns? (with Clare Farmer, 2020), Disasters That Changed Australia (2009) and The Pyjama Girl Mystery (2004).