When and how do powers manifest themselves? There are two models. The orthodox view has powers standing in need of stimuli, which once received issue in responses. This model portrays powers as passive. The stimuli are powerful, but the powers are disempowered, turning the order of explanation on its head. The second model is more promising: C. B. Martin’s notion of mutual manifestation partnering. Powers exercise when they meet their reciprocal partners and produce something jointly that they could not have produced alone. In his chapter on causation, Martin offers an analogy to explain mutual manifestation: it is like two triangular cards coming together to form a square. The triangles do not cause the square; they become the square. We argue that although mutual manifestation is the right model, Martin’s analogy of the two triangles is misleading. If we look at natural processes in which powers exercise and manifest themselves, we see that three revisions are needed to the analogy. First, the triangles need not become the square immediately. It can take time for a process to unfold. Second, powers compose often in a non-linear fashion. This would mean that the area of the square need not be the sum of the areas of the two triangles. Third, component powers needn’t be found in their resultant powers. This would be like the two triangles sometimes forming a circle rather than a square. Martin’s analogy depicted mereological composition rather than the natural processes issuing from powers and, contrary to his claim, causation is indeed the notion we should be thinking of.