For the past forty years Thom Mayne and his firm, Morphosis, have been engaged with projects that exist in the hybrid space between architecture and urban planning. Against this backdrop, Thom Mayne's new book Combinatory Urbanism: The Complex Behavior of Collective Form (Stray Dog Café, 2011) surveys 12 urban projects that range in scale from a 16-acre proposal for rebuilding the World Trade Center site after the 2001 terrorist attacks to a 52 thousand-acre redevelopment proposal for Post-Katrina New Orleans. This book and the proposals found within, posit an alternative to traditional end-state planning solutions, while attempting to not only illuminate but also explicate Mayne's own work and critical processes. Combinatory Urbanism represents a departure from previous Morphosis publications. Both a manifesto on urbanism and a comprehensive presentation of Morphosis urban design projects, many of which have never before been published; this book fills a void in the world of architectural and urban design publications.