Why an infrastructure toolbox? Infrastructure has long been a central conceptual tool—a productive metaphor—for critical theory and the analysis of social life more broadly. We speak of making concrete arguments, those (like infrastructure) that seem to offer tangible evidence of their claims. But what happens when infrastructure is no longer a metaphor? What happens to theory-making and ethnographic practice when roads and water pipes, bridges and fiber-optic cables themselves are our objects of engagement? In part, we need new tools—tools that allow us to think infrastructure’s metaphorical capacities with its material forms, and to think those material forms along with their capacities to generate aspiration and expectation, deferral and abandonment.