Photographs have been doctored, falsified, and manipulated since their invention, yet the notion that a pictured person is somehow captured by a photographic image persists. The myth of indexicality—the legacy of photograph as trace, as having a special relationship to the real—runs throughout photography discourse, specifically discourse about photographs of suffering and how viewers might respond ethically to them. In this chapter, Roland Barthes's Camera Lucida and the work of artists Josh Azzarella and Trevor Paglen are taken as examples of an alternative view of photography as limit rather than proof. Different approaches to "unknowability" and mystery then frame this limit as a resource for ethical responses to images of suffering. The chapter argues for a view of photography as a mode of representation that fails to capture its subjects and that also makes its failure visible. Photography exists at the limits of representation, revealing there is more to the subject than can be contained by the image. Understanding photography in this way provides resources for constructing a mode of looking that maintains a form of otherness based on unknowability. Instead of turning the other into whom or what viewers want or need them to be, viewers are challenged by the other's otherness—by the fact that he or she can never fully be known—and it is out of this mystery that the possibility for ethical relationship emerges.