In the past few years, the education sector, including teacher education, has encountered unprecedented challenges resulting from the global pandemic of the Coronavirus (COVID-19). In Hong Kong, it was fuelled by protests and campus occupation due to the unstable political situation. Many universities were forced to suspend face-to-face instruction and adopt online teaching. This volume is a response to the global transformation of teaching and learning from the face-to-face mode to the online mode triggered by these challenges, with a focus on teacher education in Hong Kong. This introductory chapter pulls together the narrative of the volume by detailing such challenges and showcasing how the challenges have accelerated the use of e-technology in teaching and learning online. It provides an overview of the chapters included in this volume and discusses how they contribute to the rationale of the volume and the various sections, which include challenges in teaching and learning in times of crisis, curriculum and pedagogical innovations, assessment and feedback practices, and the scholarship of teaching and learning in the teacher education context. Copyright © 2023 selection and editorial matter, Kevin Wai Ho Yung and Huixuan Xu; individual chapters, the contributors.