Three facts underlay this chapter. First, the human system and all our ambitions for improving the human system depend on sustainable natural systems. Second, we do not have much time. On track to fall well short of all sustainability goals, the climate and sustainability crises grow and extinction looms. Third, up to this point evaluation has shown little interest in sustainability, yet evaluation potentially addresses the very questions that are central to informing and guiding rapid adaptation of human behavior to successfully surmounting extinction.Business-as-usual evaluation will not suffice. At the endgame with extinction looming, we need an evaluation that is more nimble, keeps up with rapidly accelerating knowledge, is relentlessly use-seeking and that guides the way to joined-up approaches. The evaluation we need will systematically mainstream sustainability across all evaluations and interventions, in all evaluation criteria and standards. For this, all evaluations will always address nexus where human and natural systems join and incorporate knowledge and methods from both systems. Existing evaluation knowledge is well suited to this task, as are knowledges in biophysical sciences. We know and promote knowledge processes for integrative evaluation and are starting to shift toward the requirements for evaluation at the nexus. As this chapter shows, the anchors holding us back are political, not technical.