In the field of applied linguistics, Diane Larsen-Freeman is widely recognized, among her numerous contributions, as the originator of Complex Dynamic Systems Theory (CDST). Over the years since her seminal publication (Larsen-Freeman, 1997), CDST has evolved into a meta-theory that guides the field's thinking on a variety of developmental phenomena, not least the study of second language acquisition. As its theoretical potency rises, so does the need to achieve a tangible understanding of CDST's core constructs. In this paper, we empirically examine one such construct, co-adaptation, in the context of asynchronous dyadic interaction. A data corpus of 39 emails sent between two college students in China and the United States over the course of seven weeks is analyzed using NVivo 12. Co-adaptation is observed at the pragmatic, discourse, and linguistic levels. True to the spirit of CDST, we describe, and discuss the nuances of, our findings. Considering the novelty of our approach to data analysis, we end by reflecting on the limitations specific to our study, as well as worthwhile directions for future pursuits.