Requirements Engineering (RE) investigates the impact of a future-oriented change vision, but the move towards this vision must consider a context heavily shaped by the past. As RE becomes a continuous process throughout the system lifecycle, it must achieve an effective combination of envisionment and traceability. In this paper, we describe a scenario-based solution to this problem which is based on an integration of five ingredients: (a) the persistent capture of context in the form of real world scenes captured in multimedia; (b) formal agent-oriented modelling with a semantics that allows distributed interactive animation; (c) message trace diagrams as a medium for exchanging animation test cases and traces; (d) a goal model to control and record the RE process; and (e) a process-integrated tool environment to ensure method-guidance and traceability with as little effort as possible. In addition to the basics of our approach, we also describe its prototypical implementation in th...