This may be an oral history of British science, but scientists are part of a much wider networks that cross international boundaries. Our interviewees explain how scientific knowledge travels the world through journals, conferences, fieldwork, sabbaticals and jobs at foreign facilities, networks of personal contacts, and new communication technologies. They explain how this journey often has wider consequences as knowledge spreads and as expertise is shared and swapped. Some scientists find their work can only be done far from home, as visitors to highly specialised research facilities in distant countries, or on fieldwork expeditions to far flung locations. International Big Science research facilities and collaborative projects between different countries, often brought about by industrial, political and military alliances, saw British scientists work closely with their foreign opposite numbers and makecontributions to research around the world. Our interviewees' experiences of working abroad and with colleagues from different nations provide a comparative perspective on British science, highlighting the varying status of scientists in different cultures and characteristic national styles of engineering and science.