The paper explores the rise of activity-based costing (ABC). Drawing on actor-network theory, we follow key actors, and their intermediaries, as they construct ABC through a network of human and non-human allies. Drawing on Giddens' discussion of the dynamics of modernity, we show how ABC is formed, and reformed, in processes of disembedding and reembedding, and how it becomes affiliated to 'new wave management'. Through close attention to detail, our story evaporates simple distinctions between invention/discovery and theory/practice in the development of management accounting. We portray ABC as a socio-technical expert system that is formed mutually with the construction of the actor-networks that create it. As an expert system, ABC is both a response, and a contributor, to risks of the modern world - a bandwagon hitched to a juggernaut.