In an era of increasingly interconnected knowledge-work, and more frequent interdisciplinary research collaboration, what role can and does English play? Interdisciplinary collaboration is notoriously difficult, and knowledge flows between disciplines have been critiqued for privileging certain voices from certain contexts (geographic and disciplinary) in certain languages (e.g. English), thereby raising the possibility of epistemic injustice. English, as the global language of our time, is at the interface of such concerns. It is also a major medium for intercultural encounters of an inter-knowledging character. What happens when ideas from one discipline are brought - through the medium of English - into another? And what are the implications — for English language specialists (including teachers, translators, and researchers) — of the role of English in such encounters? In this paper, I consider such questions with reference to research projects in which I have recently collaborated.