In this chapter, I introduce the topic of negative action. I provide a rough account of the distinction between positive and negative actions, of the distinction between two commonly-discussed kinds of negative behaviour (omitting and refraining), and of what distinguishes negative actions from mere failures to do something. Then, drawing on this discussion and the discussion of Chapter 1, I articulate the problem of negative action: negative actions seem to be genuine actions; actions seem to be events; but (at least some) negative actions seem to be, not events, but absences thereof. I trace the widespread acceptance of the latter claim to Deflationism, the view – often held only implicitly – that negative action sentences express negative existentials.