This episode explores areas that have never been filmed before, following British head of maintenance Vince - the man charged with keeping the tunnel moving - and one of its longest-serving engineers, Richard, who helped to build the Tunnel back in 1988.

This episode follows the struggle at Britain's border during the first summer since the camp known as the Jungle was demolished, and the first since Britain decided to leave Europe. For how much longer can Britain keep people who want to come here over there? Cross-Channel ferry captain Mark and his crew guard their ship from migrants desperate to board it. The programme also meets Stuart, a businessman from Surrey who runs a private high-security truck stop in Calais where drivers can have their vehicles checked for migrants.