The existence of "the sign" generally tends to be taken without questions. In this study I show that signs are born in and for activity, where they are part and constitutive of the relation with others. I use a brief case study as the empirical basis to suggest an approach grounded in cultural-historical and pragmatic approaches that abandon the notion of signs as mediators and instead focus on the developing communicative field that is common to the participants in relation. Abandoning the sign as mediator allows us to pursue studying the lines of becoming that were so dear to the late Vygotsky, who was in the process of replacing his earlier mediational approach to the sign by a Spinozist-Marxian approach.