Contrary to widespread belief, human trafficking operations are characterised by significant costs, particularly monitoring costs, and diseconomies of scale. How do traffickers achieve high capacity in their operations? This paper is an empirical in-depth study of the structure and activities of a large-scale human trafficking ring operating between Nigeria and Europe. It is based on a set of novel data sets that was manually coded and analysed using network analysis techniques, and shows that high trafficking capacity is associated with a high level of externalisation of activities. Offenders mostly act as independent agents, in a similar way to contractors. The trafficking ring does not appear to be run along ethnic or family lines, but what does emerge is a rather clear division of labour and role specialisation. Finally, the paper contributes to the broader debate on coordination in illegal settings and puts into question the idea that transnational crime is invariably best fought transnationally.