We live in an age where emotional literacy and legibility is highly desirable, and where so-called Emotion Detection technologies lead us to believe that, with enough data, we might crack the enigma of other people’s emotions. This chapter begins from a different proposition: what is it to want to remain emotionally inscrutable? Beginning with Darwin’s 1872 observation that studying other peoples’ emotions is ‘difficult’, the chapter then argues that ambivalence and illegibility is part of the nature of emotion itself. It then moves to consider a series of moments when people have deliberately used emotional inscrutability as a form of self-defence and defiance, including in ‘camp’ retorts by early twentieth century cross-dressers, and in Audre Lorde’s refusal to emotionally engage with white women about race because it came at such a high psychological cost to her. In this way, this chapter shines a light on those moments when emotional inscrutability becomes a powerful political tool.