In taking properties to have powerful or dispositional essences, dispositionalism is primed to provide an account of causation. This paper lays out a challenge confronting the dispositionalist’s ability to account for how powers causally interact with one another so as to bring about collective results. The challenge, here labeled the “interaction gap,” is raised for two competing kinds of approaches to dispositional interaction: contribution combinationist and mutual manifestationist. After carefully highlighting and testing potential resources for closing the interaction gap, it (...) is concluded that the mutual manifestationist approach holds a significant advantage. In turn, the importance of the interaction gap itself is highlighted. While powers prime an ontology to yield an account of causation, how far that account can actually go depends on the metaphysical details of one’s view of powers and their causal interaction. (shrink)