The third and final section of this book is based on the observation that interactive processes involve a large number of elements, related to language, but also to other semiotic fields. Interactions are embedded in contexts and contain activities and actions. Participants are characterised in a multitude of ways and their objectives unfold over time. These heterogeneous elements are also linked by multiple relationships that may also evolve thus satisfying one criterion of a complex system. Emergence is also key as researchers describe unexpected or unpredictable phenomena, either fleeting or that provoke a complete restructuring of the interaction. The chapters in this section focus on a variety of interactional and linguistic analyses on empirical data that question models or will otherwise elaborate on the theme of complexity, interaction, and multimodality.