In this interdisciplinary study, the authors argue that Hong Kong must develop and strengthen the mobility, broadly defined, of its population. This is at the heart of its need to face the challenges from a changing global environment. Being a “space of flow” and a place of mobility has always been an essential characteristic of Hong Kong and the root source of its success. This uniqueness, it is argued, must go hand in hand with enhancing its institutional resources that its regional competitors have yet to develop. It uses historical data to argue that “One country, Two systems” is a concept not uniquely reserved for post-1997 Hong Kong. The territory has thrived on being simultaneously part of China and the world. It has been a node in the crossroads of empires, trading communities, industrial assembly lines, and now global finance, consumption and media. The book, using meticulous analysis of census data, shows that a porous border in fact has been maintained through the post-war years, with waves of immigrants entering from China. However, the study warns that the population is now ageing when compared with other world cities and China’s fast-growing urban centers. Without massive input of young, educated, and diverse human talents, Hong Kong will lose its strategic positioning in the region. Only with such inflow can Hong Kong remain, as it historically has been, a vibrant space of flow of capital, goods, people, information, services, global cultural horizons, creative aspirations and civic energies. Hong Kong has met its past challenges through an institutional structure that is conducive to legal and business integrity, educational openness, high professional standards and cultural diversity. With mobility encouraged and institutional resources enhanced, those who exit and enter the territory during different phases of their education, lives, and careers will deposit value to local society and connect it to regional and global environments, making it a hub of hubs.