I will explore different aspects of unitarity in expanding cosmologies.  First, I will argue that time evolution in quantum mechanics is always isometric, in the sense of preserving inner products, but not necessarily unitary.  Evidence for this hypothesis can be seen in several technically and conceptually distinct examples.  I will also discuss models of emergent unitary in low-dimensional gravity, and explain connections to recent work on wormholes and the factorization paradox in AdS/CFT.