This article explores a research alliance across fields and continents in the wake of the early and controversial HIV-prevention clinical trials of pre-exposure prophylaxis (PrEP). Our research set out to understand why three trial arms prematurely closed while another was refused approval from the relevant institutional review board. We conducted ethnographic research on ‘what happened’ at two of the sites. Over time our research strategy cohered around unearthing and exploring rapidly disappearing knowledge. We analyze insider/outsider politics, the power of global public-private partnerships, and the forms of scientific knowledge (located in African countries) that get left behind in the process.