The National Audit Office (NAO) is now over 40 years old, but it has its origins in the nineteenth century. In their new book, Henry Midgley, Laurence Ferry and Aileen Murphie offer an overview of the constitutional, political and human legacies of the NAO’s predecessor, the Exchequer and Audit Department, followed by a close examination of the NAO’s leadership and decision-making since its inception. They conclude that any debate about the organisation’s future is in fact a question about how the UK should be working to ensure democracy and good government.