A London taxi is a flying bomb. The comparison rose in him slowly, from deep in his unconscious memory. The clatter as it barges into the crescent, the metric tick-tick as the bass notes die. The cut-off: where has it stopped, which house, when all of us in the street are waiting in the dark, crouching under tables or clutching pieces of string, which house? Then the slam of the door, the explosive anti-climax: if you can hear it, it's not for you. But Smiley heard it, and it was for him. -- John le Carré, "Tinker Tailor Soldier Spy"