Yrjö Engeström (2014) describes three “generations” of activity theory. First was Vygotsky’s work, which was centered around the concept of mediation, but limited to individuals or dyads. Second was Leontiev’s development of the theory, which introduced the unit of analysis (labor activity) and expanded it to apply to groups. Third was the work of Engeström and others in the West, who expanded the theory to address multiple interacting activity systems. The story is that of linear development and expansion of Vygotsky’s fundamental psychological insights to address broader social systems. Yet that development has not been linear at all. In each generation of activity theory, the extraordinary – the remarkable phenomenon that provides the center of gravity of the theory’s development – has changed. In this chapter, I examine the development of the extraordinary across the three generations of activity theory, identifying key inflection points in this development. I conclude by discussing implications for developing activity theory further.