This book’s 31 chapters reflect trust as an important and vibrant field of study, both in terms of what has already been done, but more significantly in the fruitful future research agendas our contributing authors have outlined. The chapters that comprise the book’s six parts highlight some of the foundational approaches and building blocks in this field. In this last chapter, we do not merely repeat what our contributors have identified, but instead offer a meta-level perspective that identifies eight challenges and future directions for study.