Book excerpt: When manufacturers and retailers vacate traditional locations, they leave holes in a city's fabric that signal a shifting urban-industrial terrain. Who should mend these spaces, and how should they approach the problem? Using Toronto's Dundas Square and surrounding area as a case study, this book meticulously reconstructs the redevelopment process to explore the theories and practices used. It traces the labyrinth of competing interests that can sideline and nearly overwhelm the public planning function. In these circumstances, Moore Milroy concludes that practising planners are marooned by planning theories that begin from the premise that urban space is a social construction and only secondarily a function of technology and aesthetics.