Constant Wanderlust

"Without people like me, underground travellers, London would not work. If the subsoil did not seethe with trains, did not suck in and circulate a huge population of its own, the superficial metropolis - the landmarks, double-decker buses, skyscrapers and fountain-filled squares - would grind to a halt. London’s heart is under its earth, and some days catching that Northern Line made me feel essential, like blood."