As one of the most devastating, deactivating, and disturbing negative emotions, boredom is common to all human beings and metaphorized as "the psychological Sahara" (Brodsky cited in Pawlak et al. 2020c: p. 3). It has long been examined in philosophy, literature and educational psychology. Although research into negative emotions is increasing in language teaching and learning, boredom is still under-researched, as the authors stated in the preface. This is part of the rationale for the authors to devote this book on boredom from the foreign/second language learning perspective.All three authors of this book have continuously endeavored to research boredom in L2/EFL settings, which guarantees the credibility of the book. While building on their previous studies (Pawlak et al., 2020a(Pawlak et al., , 2020b, the book further contributes to the existing literature by adopting a micro-perspective. Through investigating boredom in a specific context with data collected from various resources, such a perspective can help delve deeply into the complex construct of boredom and reveal its intricacy in great detail.The purpose of this book is twofold. First, it aims to explore the dynamics of boredom experienced in two naturally occurring English lessons by two groups (11 females and 12 males) of final-year undergraduate English majors in a Polish university. Second, it attempts to discover the factors contributing to the fluctuations of L2 learners' experienced boredom in the instructional setting.This book comprises five chapters. Chapter 1 begins with the theoretical underpinnings of boredom, including definition, classification, causes of boredom, and other relevant emotions, such as dis/engagement and disaffection. It then moves on to a comprehensive review of empirical studies on boredom in educational psychology and L2 learning (Chapter 2). Chapter 3 describes the research design, instruments, data collection and analytical procedures of the project; this is followed by a detailed discussion of the findings (Chapter 4). The book closes with an overview of the project, directions for future research, and pedagogical recommendations for coping with boredom (Chapter 5).This book has several strengths. One is that it offers an in-depth and comprehensive review of both theoretical and empirical studies on boredom, upon which the authors have revealed its complex and multifaceted nature. To pinpoint the description of boredom, the authors examined a vast number of studies in educational psychology and L2 education, displayed the typology, the relationship among each type of boredom, and summarized various intensities of boredom presented in those studies in a logical manner. This could help readers build a clearer understanding of the conceptualization of boredom and prepare the ground for the following chapters that explore boredom empirically.The second strength of this book is its innovative approach to probing boredom in foreign language classrooms from a micro-perspective, which offers methodological insights. Acknow...