Media frauds often lead to lively public discussions about journalism’s professional identity and its social mandate. The paper uses the so-called Relotius case as a starting point for a systematic analysis of the responsibility of narrative journalists in an age of “fake news” and post-truth politics – and the question of how they can be held to account in the online realm. Claas Relotius counted as one of the most talented journalistic storytellers in the German-speaking world. In December 2018, however, the news magazine Der Spiegel revealed that he had fabricated many of his texts, either completely or partly. This revelation developed into one of the biggest German media scandals of the recent years and triggered a massive outcry, also in international media. A multi-method research design allows for a differentiated assessment of the Relotius case in particular and web-based media accountability processes in general: A literature review and problem-centered interviews with senior reporters demonstrate that stylistic devices of fiction have a long history in German narrative journalism – also in Spiegel magazine. A discourse analysis focusing on the public debate following the revelation of the scandal points out that many journalistic commenters, including Spiegel’s editorial board, displayed a clear lack of self-criticism in their discussion of the case, while non-professional watchbloggers broadened the scope of the analysis. The paper reflects the empirical results from a normative perspective, in order to illustrate the potentials and shortcomings of professional journalistic self-observation as opposed to external public control in online discourses.