The interior is often described as a slippery subject (Hollis 2007: Edwards 2011: Rogers 2012), a suggestion manifest in the frequently expressed view that it lacks a historical, theoretical and regulatory foundation. This presentation will suggest that this fluid quality is actually the raison d’être of the subject. It posits the notion that this spatial ambiguity is fundamental to the comprehension of the interior condition. In this presentation I will use my research and teaching to examine how Impact, defined as process of a forceful impression, is closely related to Agency, the production of a particular interior sensibility.