This chapter takes the example of the International Criminal Court’s ‘Independent Expert Review’ (IER) of 2020 to reflect on the theory and practice of expert reform work. Taking actor-network theory’s prompt that systems – like international organisations – are neither static nor fixed, but ‘in a perpetual state of forming and reforming’, I read reform neither as rational science nor as a mere reproduction of hegemony, but as the expert reassembly of the ICC’s context, problems, resources, and priorities. In the IER example, the expert work of reform and reassembly effected nothing less than the recalibration of the relationship between the Court and its states parties. Through their work, experts knit together ideas of autonomy and accountability, their training, investigatory processes, documents, and resource and time constraints to centre the efficiency concerns of wealthy states parties in the judicial and prosecutorial function. In this way, expert reform work illustrates the power of expert articulation by putting abstract expectations, ideas, ‘realities’, constraints, and materials into organisational action in deeply distributive ways.