Linguistic diversity in many schools is high such that science teachers face complex issues regarding appropriate ways of mediating social and academic language in multilingual classrooms. The relationship between these aspects and the task of teaching science (i.e., pedagogy) remains a mystery to many teachers. This paper provides a narrative and shared discoveries of the understanding of this differentiated instruction problem in order to forge the path ahead. Qualitative methods of lesson observations and semi-structured interviews were used to collect data from four participants in the province of KwaZulu-Natal, South Africa. Analysis of data revealed a domination of English as a medium of discourse. The paper argues that teachers' pedagogy and language of instruction are essentially related to the quality of science being taught in multilingual classrooms. The findings highlight the fundamental importance of the language of instruction within a multilingual science classroom and lay a foundation for further research.