-- The conjunction of three plausible theses about the nature of causal powers---that they are intrinsic, that their effects are produced mutually, and that the manifestations they are for are essential to them---leads to a problem concerning the ability of causal powers to work together to produce manifestations. I call this problem the problem of fit. Fortunately for proponents of a power-based metaphysic, the problem of fit is not insurmountable. Fit can be engineered if powers are properties whose natures are determined holistically. However, this power holism does not come without a cost, as a power-based metaphysic must be supplemented by a certain amount of additional machinery in order to avoid the problem.