A major problem associated with the planning of megaprojects is the high level of misinformation about costs (and benefits) and the high risks such misinformation generates. And Decision makers often doubt the utility and necessity of such projects. This study seeks to investigate a controversial state-of-the-art megaproject, Amager Bakke, which assumed to be successful by many in the beginning, but it turned upside-down. This project has had political and industrial attention at the highest levels both regionally and nationally, including ministers and industry. After the analysis two discourse coalitions were identified that display opposing storylines. By Investigating the interplay between storylines the dominant discourses were identified, power-relations become unlocked, planning styles were distinguished, tension points were revealed and the consequences of the argumentations recognized. The aim of this study was to make a contribution to megaprojects planning and decision making in the face of risk and uncertainty.