It started with a simple observation: Students need their teachers present to answer questions or to provide help if they get stuck on an assignment; they don't need their teachers present to listen to a lecture or review content. From there, the authors began the flipped classroom. Students watched recorded lectures for homework and completed their assignments, labs and tests in class with their teacher available. What they found was that their students demonstrated a deeper understanding of the material than ever before. This is the authors' story, updated and expanded, to ensure it's as relevant to your classroom as ever.