In this paper, we analyze intermediary work in the context of sustainability transitions in relation to what we call the “environmental paradox”. While sustainability transitions are strongly related to political or social expectations in terms of management performance and measurable results and effects, environmental problems have some generic characteristics which make these expectations partly unachievable. Those recover the notions of interdependency, complexity, uncertainty and controversy. We argue those key features condition understanding and concrete achievement of intermediary work. Drawing upon biographic narratives of intermediary actors (extension worker, mandated intermediary workers, group of experts and researcher, NGO member), we use contrasting examples to propose a comprehensive reading of what makes their strategies effective regarding the development of political narratives and of learning processes in the context of the management of ‘wicked problems’. Our crosscutting approach allows us to advocate that such an intermediary work cover a set of roles or functions which involve strong articulation of objectification processes with inter-subjectivation. Then, the properties of intermediary work may be regarded as the capacity intermediary workers develop to contextualize their own activity, to create the conditions of their own performativity, both being strongly related to intermediary workers reflexive consciousness.