In 1927 some of the great names of physics such as Albert Einstein, Niels Bohr, Marie Curie and Ernest Rutherford gathered in conference with other scientists in Brussels. The revolutionary new theories of the structure of atom and quantum mechanics were debated openly and dispersed internationally. But by 1939, as nuclear fission was discovered, a new generation of atomic physicists emerged but were kept from conference by the looming shadow of war. Mark Oliphant, who was later the foundation chair of Physical Sciences at ANU, was among them. Extraordinary international networks were established, which transcended national borders and censorship attempts of both the Axis and Allied powers.  Through these scientific networks, the whisper of radical ideas of atomic science spread like a contagion, often in defiance of the state. The ‘invisible college’ established by Oliphant and his colleagues can be mapped by sociological tools such as small-world network mapping. In this paper I will demonstrate how the long reach of tight networks can be read across history, and how this transforms our understanding of censorship and control in mid-century atomic science.