European integration visualized through the prism of high-skilled labour mobility, using official EU records from the post-enlargement period 2005-2014. Countries are denoted as peripheral arcs, sized proportional to total incoming and outgoing mobility, connected by links with width proportional to the directional inter-country mobility. Image developed by A. M. Petersen. See Petersen AM, Puliga M. 2017 High-skilled labour mobility in Europe before and after the 2004 enlargement. J. R. Soc. Interface14: 20170030. http://dx.doi.org/10.1098/rsif.2017.0030.