There are 4,500 railway arches in and around London that witness an astonishing range of activities, from the mundane to the outrageous. This film meets some of the occupants of this netherworld who use their personal space in a variety of ways. Brian sells a whole range of second-hand goods, Master B indulges his sexual proclivities, Robin relaxes by practising his golf on a driving range, while Ian makes coffins.