The chapter argues that anti-corruption crusades are characterised by extraordinary levels of prosecutorial zeal and reliance on aggressive tactics; high degrees of coordination between law enforcement agencies; evidentiary snowball effects leading to protracted and uncertain inquiries; and disruptive consequences beyond the courtroom. With this in mind, the chapter introduces two research questions. First, under what conditions are corruption probes more likely to evolve into crusades? Second, the stated objective of crusades is relatively uncontroversial, but their aggressive methods, choice of targets, and the intricacies of the legal process are not. Moreover, results often stand on precarious grounds. Given their provocative, disruptive, and uncertain nature, how do crusades impact attitudes and emotions towards politics and corruption? Do voters become more cynical or hopeful about the future of politics? After summarising our argument about the causes and consequences of crusades, and describing the books’ empirical strategy, the chapter discusses the main contributions to the study of anti-corruption, judicial politics, and political behaviour.