The efficacy of antibiotics is eroding. Not merely a health or medical issue, antibiotic resistance is now a widely ramifying security and scientific issue. This project examines an emerging “post-antibiotic era” as a problem of planetary insecurity, a time in which common infections and minor injuries can, within a century of the mass development and deployment of antibiotics, once again kill. Yet, this time also presents moments of possibilities, causing a resurgence of interest in moribund, alternative techniques and epistemologies of infection control such as bacteriophage therapy that have long been cast aside as superfluous knowledge. These “bacteria-eating” viruses—found abundantly in nature, and used extensively in genetics research—once functioned as an alternative, ecological tool for controlling infections in the former Soviet Union. However, bacteriophages were not a popular form of medical intervention elsewhere during the Cold War. As this research reveals, the viruses, themselves, have a more complex history of religious-scientific origins in India, in rivers such as the Ganga and Yamuna, whose believed curative propensities have long held mythic and medical significance in local epistemic contexts long buffeted by colonial encounters. Phage therapy did not gain traction in the West during the Cold War for ostensibly geopolitical reasons, and the use of bacteriophages or antibiotics were largely political decisions. With the end of the Cold War and the crisis of antibiotic resistance on the rise, bacteriophage therapy—once an “inferior” science—is now emerging as a revenant medical, biosecurity, and biotechnological strategy from India to the US to its epicenter, Georgia. Long divided by geopolitics and quality of life, these allegedly-Third, Second and First worlds no longer adhere to those logics or hierarchies. Instead, they are now interconnected by "emergent forms of life" featuring bacteriophages as a promising frontier in post-antibiotic worlds. This project pursues transnational studies of health and disablement; environmental anthropology; and critical theories of science and rationality. It proposes an intercalated relationship between scientific epistemologies, technological materials, political histories, cultural practices, and planetary futures. By summoning wider conceptions of the complexity of nature, ecologies, and human-bacterial-animal-viral entanglements, it seeks to offer informational resources and socially-grounded strategies to confront antibiotic resistance at various scales.