An irregular thumping noise was emanating from somewhere, not inside this building but nearby. At first she heard it only subliminally, since it was buried in ambient sound from the street. But as she dragged the exhausted and irritable landlord skyward, this sound began to break clean from the clamor of the street and to enter her consciousness. The thumping started and stopped. It would go for three or six or ten beats, like the pounding of a heart, then cease for a little while, then start again, sometimes faster and sometimes slower. Sometimes it terminated in a faint crashing noise. She knew the pattern well because she and her colleagues in London had heard it in the background of Abdallah Jones’s recorded phone conversations and had devoted many hours to wondering what it was. Their first thought had been construction noise from a neighboring apartment, but it didn’t really fit that pattern; what sort of construction used only hammers but never a saw? Perhaps Jones lived upstairs of a butcher shop where heavy cleavers were being used to whack apart big carcasses? Or a martial arts dojo where students were hitting a punching bag? They had never really been able to pin it down, and it drove them crazy.