The direction in which the structure of sentences and filler-gap dependencies are built is a topic of fundamental importance to linguistic theory and its applications. This book develops an integrated understanding of structure building, movement and locality embedded in a syntactic theory that constructs trees from the top down, presenting an explicit counterweight to the bottom-up derivations pervading the Chomskian mainstream. It combines a compact and comprehensive historical perspective on structure building, the cycle, and movement with detailed discussions of island effects, the typology of long-distance filler-gap dependencies, and the special problems posed by the subject in clausal syntax. Providing introductions to the main issues, reviewing extant arguments for bottom-up and top-down approaches, and presenting several case studies in its development of a new theory, this book should be of interest to all students and scholars of language interested in syntactic structures and the dependencies inside them