Using official documents, institutional analysis, and interviews, the chapter traces Peru’s Lava Jato, the most ambitious branch of the inquiry outside Brazil. A sequence of organisational changes within the prosecution services created a more hospitable environment for proficient and innovative anti-corruption efforts. A process of bureaucratic differentiation nurtured interstices of investigative capacity, despite enduring corruption at the top of the institution. However, Lava Jato struggled to take off until all lines of inquiry were placed under the purview of a taskforce. Within case variation in this aspect of the investigative strategy shows the benefits of teamwork , as well as the role of individual personalities and professional role conceptions in determining the outcome of corruption probes. One consequence of the decision to pool investigative resources was a more aggressive and coordinated fact-finding approach. Finally, the case study shows that while prosecutorial zeal was critical for the progress of the case, it also invited backlash and risked jeopardising the legitimacy and effectiveness of the inquiry at various stages.