Transitional justice comprises diverse mechanisms whereby new democracies might address their former authoritarian past. This excellent book addresses the highly policy-relevant question of which mechanisms are best suited to improve the quality of democracy under which circumstances. Nalepa makes a compelling case for distinguishing between four mechanisms, depending on whether they target secret or open collaborators of the former regime and how far they reach into the population. Her main expectations are two-fold: First, transparency mechanisms, including lustration and truth commissions, expose former secret collaborators and reveal 'kompromat'. Thereby, they reduce the susceptibility of elected politicians to blackmail, enable them to represent voters more faithfully, and improve the quality of democracy. Second, mechanisms that remove known members of the old regime through purges entail a more difficult trade-off: they may increase the bureaucracy's loyalty to the new democratic regime, but also entail a loss of expertise. Hence, 'transparency should be used widely', while 'purges should be applied sparingly', especially if bureaucrats' expertise is valuable and their loyalty to the former regime weak. To derive and test these expectations, Nalepa combines an impressive array of methodologies. She relies on formal models to clarify her arguments. She constructs a rich global dataset that breaks down all four transitional justice mechanisms into discrete events. Finally, she provides large-n evidence for her argument and complements this with discussions of six archetypical cases: Bolivia, Poland, Tunisia, South Korea, South Africa, and Spain. Future research might build on Nalepa's important findings by investigating how transitional justice mechanisms affect additional dimensions of democratic quality, for instance the institutionalization of liberal rights and freedoms, the emergence of civil society organizations, and the system of public debate.