The paper uses interviews and observational data gathered among a group of UK scientists and civil servants responsible for managing a study examining the possible transmission to humans of Borna disease virus (BDV), a disease primarily of farm animals. From a science and technology studies perspective, the paper examines the social processes whereby this scientific problem (possible human transmission) was constituted as a worthy topic of scientific investigation, came to receive funding, and was subjected to independent review. It appears that BDV research displays only some of the characteristics of 'post-normal science' with little participation by extended peer communities. Civil servants and scientists reported social interests that were complex and both fractionated and cross-occupational. An important motivation for engaging in the research was the need to maintain investment in pre-existing scientific resources (assay development, virus stocks and an existing epidemiological cohort). In respect of translation theory, influence was a two-way street, with civil servants eager to enrol scientists and represent the interests of science, and with scientists presenting themselves as defenders of the public good. Despite the dynamic character of scientific debate, the 'career' of BDV investigation appears to have ended in disengagement, rather than closure.