Management research is increasingly using fiction as an insightful way to analyze complex organizational dynamics. Focusing on user appropriation of Knowledge Management Systems, we describe how we used the popular Astérix, a well-known French cartoon to better understand KMS appropriation. We came to use this approach in an action research project in a large French construction firm initially designed to help Chief Knowledge Officers address KMS non-use. After our first findings showed paradoxical cultural issues, and based on the idea that culture is central to sensemaking and appropriation, we used the notion of the cultural metaphor to help better understand the cultural aspects associated with KMS appropriation. These results contribute knowledge in three different areas. First, we underline the role of cultural metaphors in information systems appropriation. Second, we enrich the literature on the role of fiction in management by illustrating the role of cultural metaphors. Third, we report on how this can be used in an action research project to help better understand KMS appropriation issues, which has the potential of leading to practical managerial action.