This book is about a lost world - albeit one less than 50 years old. In the era of Harold Wilson's 'white heat', architect Sir Leslie Martin proposed a grand plan to demolish and rebuild a swathe of historic Whitehall, London's government district. At once optimistic and paternalistic, it simultaneously reinforced and challenged a rigidly hierarchical social order at the scales of building, city and nation. This project was never realized, but nevertheless, the plans and the political history surrounding them offer unique insights into Wilson's government, Wilson's Britain and Martin's distinctive scientific model of architecture, and more broadly into the connections between architecture, politics and society.