One of the salient developments in recent metaphysics is the increasing popularity of material plenitude: roughly, the thesis that wherever there is one material object there is in fact a great multitude of co-located but numerically distinct objects that differ principally in which of their properties they have essentially and which accidentally. Here I argue that we have at least as much reason to look favorably on event plenitude: wherever one event occurs there occur a great multitude of co-located but (...) numerically distinct events that differ principally in which of their properties they have essentially and which accidentally. I argue, first, that the standard reasons to adopt material plenitude extend fairly straightforwardly to events, and secondly, that only event plenitude can protect the plausible idea that causality is an extensional relation. (shrink)