It is a walled city, this city beneath the city of New York. Its southern wall stands thick and strong, composed of the remains of the wall that once lined Wall Street, the old fortifications built long ago by the settlers of New Amsterdam—back when the greatest sign of a city’s strength was what it was capable of keeping out, rather than what it was capable of letting in. As we have said, the lost city is a walled city, but only nominally so. The city is so crowded, so overwhelmingly full, so teeming and screaming and churning and burning with all that we have now forgotten, that it spills out over its walls, the wretched refuse of its teeming shores pushing out in every direction until the walls surrounding its inner core become little more than a technicality. In this underwater sanctuary, however, the huddled masses all breathe free. Its citizens, their bodies remembering the form of a fetus inside a saline womb, breathe through gills in their half-severed necks.

The language spoken here varies from time to time. In the beginning, it was the chirping of birds, vast flocks of birds, sent down below by slash-and-burn farming above. Then, and this has been true for centuries, the lingua franca of this lost city became Manhattan. No, not some metaphorical imaginary language of wealth and poverty and crime and art, but the actual language Manhattan, spoken by the Manhattan tribe of natives who gave up the island a few hundred years ago for sets of beads worth approximately twenty-four dollars. (Some residents of the lost city, the municipality’s much-envied elite, wear these beads around their necks.) Of course, other languages are spoken here too. A few hundred citizens speak seventeenth-century Dutch; a dozen or so pride themselves on having mastered Esperanto. And lately, more people are picking up Yiddish.

Outside the walls, the road to the lost city underneath New York is paved with tefillin.

LEORA ENTERED the lost city almost unnoticed. The gatehouses of the city—staffed, she was later informed, by suicides—do not guard the doors very carefully, and the guard on duty when she entered was especially inattentive. The guard, a handsome man in his forties with a graying mustache and bright blue eyes, was engrossed in reading something. From her position, it was hard to tell what it was, but as she drifted up a bit in the water while trying to sneak through the gate, she caught a glimpse of German words—something dense, with footnotes. But then the guard caught her eye and slammed the book shut, covering its title with his arm. “What do you want?” he growled.