The second edition of this popular text, updated throughout and now including Covid-19 and the 2020 presidential election and aftermath, introduces students to the research into conspiracy theories and the people who propagate and believe them. In doing so, Uscinski and Enders address the psychological, sociological, and political sources of conspiracy theorizing. They rigorously analyze the most current arguments and evidence while providing numerous real-world examples so students can contextualize the current debates. Each chapter addresses important current questions, provides conceptual tools, defines important terms, and introduces the appropriate methods of analysis.