This chapter analyzes the level of coordination reached among accountability institutions in Brazil during Lava Jato, mainly: the Public Prosecutor’s Office (Ministério Público Federal, MPF); the Federal Police (Polícia Federal, PF); the Office of the Comptroller General (Controladoria-Geral da União, CGU); the Federal Court of Accounts (Tribunal de Contas da União, TCU); and the Attorney General of the Union (Advocacia-Geral da União, AGU). I discuss the extent to which this operation represented a turning point in the history of the Brazilian web of accountability institutions towards a high level of coordination. In order to exemplify a situation in which the coordination was decidedly required, I discuss the juridical insecurity involved in the negotiation of leniency agreements and how the institutions have sought some level of coordination to diminish it. Notwithstanding, I also discuss the grey zone in which too much coordination turns into encroachment of accountability roles. I particularly examine whether The Intercept’s revelations could point to such a situation, pointing out institutional reforms to address this problem. In the end, I consider whether the Brazilian web of accountability institutions could benefit from the “Madisonian spirit”—the prudent disbelief in the republican inclinations of the accountability agents themselves. In this sense, I discuss whether the effectiveness of horizontal accountability could be contingent to vertical accountability—the citizenry, the elected representatives, the media and civil society.