This chapter discusses the value of posthuman sensitivity on cross-disciplinary research teams. It offers a background discussion of the Frontiers in Earth Systems Dynamics (FESD) research project team's makeup and its goals to provide some context for revisiting the FESD data set. The chapter also offers readers a posthuman strategy for mapping an ecology of language use on a cross-disciplinary project team that highlights pathways for identifying and examining the trials of strength that occur between the various actants in the research project. It discusses the implications to TPCs of cultivating a posthuman sensitivity not only in themselves but also in their cross-disciplinary collaborators. The chapter notes how such posthuman sensitivity can help TPCs heighten their legitimacy and power in complex, cross-disciplinary work where access is constrained. It assesses how the investigative team conceptualized and uses a language corpus of oxygen-related concepts and processes that were central to the team's work.