In this article, we explore processes of innovation - which are inherently uncertain - from a complexity perspective, in which they are understood as new patterns of experiences as they emerge in human conversational interaction. We reflect on local interactions between people involved in emerging processes of innovation, with a particular emphasis on the improvisational nature of interaction. Through an abductive approach, by iterating actual experiences and our understanding of them, we show that such processes are collective efforts that take place as informal, highly improvised conversations - happening 'below the radar' - which may unpredictably offer windows of opportunity to enable change. We show that innovation often emerges as 'shadow themes', experienced as subversive by those involved in the moments of interaction. While these themes are embedded in informal conversations and processes, they can be induced by invitations - conscious or unconscious moves that encourage those involved to make spontaneous moves together in a mutually improvised context. Our experience shows that the emergence of shadow themes can have a long-term impact on the organization and the people involved, and that managers may be 'in charge but not in control' of such innovation processes.