 Anyone trying to come to an understanding about what quantum mechanics says about the world has to grapple with one remaining fact. This problem is not an issue with Hilbert spaces, but of the dynamics – the rules that describe the trajectories that systems follow through the space. From a physical point of view, it is far more worrisome than anything discussed to this point. It not only presents difficulties to someone trying to provide an interpretation of the theory, but also seems to point to a logical inconsistency in the theory’s foundations.