Through investigating citizen involvement processes in a coastal protection project in the Danish municipality of Dragør, this thesis finds how concerns and arguments are brought forth in and around the citizen involvement, what role different types of knowledge plays and how insights from the particular case of Dragør can help inform future project concerning citizen involvement. Through this extreme case, we produce insights on what happens when highly engaged citizens participate in an extensive involvement process created by a municipality that allocates many resources in hopes that the involvement will help solve a contested technical and social issue. By doing a techno- anthropological field study, encompassing field and virtual observations, interviews and study of technical reports, the thesis unearths the impacts of the citizen involvement through the lenses of STS. By juxtaposing the hybrid forum of Callon et al. with Jasanoffs idiom of co-production, informed by Marres’ work on issues, the thesis identifies three types of knowledge, that through encounters can generate scepticism but also hold promise for more robust knowledge production. The outcome hinges on the format of the involvement and whether citizens are invited to renegotiate framings of the project. The thesis lastly discusses the need for transparency in citizen involvements and recommends more work in understanding transparency in-the-making, to help future citizen involvement projects.