We seem to be faced with an impossible task: to determine the precise microphysical model of dark energy. I will argue that, nevertheless, it may be possible to determine certain features of the nature of dark energy. In particular, and in light of recent cosmological data, I will show that it is unlikely that the dark energy is a simple, minimally coupled, “thawing”, scalar field. This means that there is scant evidence for, for example, rolling scalar fields like axions or other such simple models. A careful analysis seems to indicate a very strong preference (on any measure) for a non-minimally couple scalar field which brings with it a host of undesirable properties: time varying Newton’s constant and fifth forces. We will show that there are ways of getting around these problems, but we are left with the unwelcome requirement of further new physics on non-cosmological scales. I will conclude by surveying the narrow range of options that are available to explain current cosmological data.