On maps that still include the Westside, it’s called Fourteenth Street, but to the warriors of the Westside, it is the Borderline. Below it: liquor, darkness, and fun, protected by boys playing soldier. Above it: candlelit respectability, policed by the rainbow-uniformed guards of Glen-Richard Van Alen.

I crossed over at Eighth Avenue, where the Jackson Square Gophers held the line. Their chief, whose smeared ocher war paint couldn’t hide his acne, glared at me as I passed.

“What business you got in the Upper West?” he said.

“None of yours.”

“We got a right to know. We got special dispensation from Barbarossa herself to patrol—”

He was taller than me, but not as heavy. I shoved him hard, square in the chest, and he fell on his back, and the laughter of his lieutenants froze him to the spot. The crossing was open.

Broken glass and twisted metal studded the intersection, thick enough to slow an attack from either side. A crooked path wound through the debris, carrying me into the shadow of the ramshackle wooden platform at the center of the road. Two stories high and nearly as wide as the avenue itself, it held a great cast-iron brazier, which at night burned bright enough to illuminate the darkest corners of Fourteenth Street. There was one at every intersection: symbols of Van Alen’s promise to beat back the night. Uniformed firekeepers scurried over its catwalks and rope ladders, bringing up the day’s wood: fresh-cut timber, unfinished lumber, and smashed furniture looted from houses all over the Upper West. By dawn, Van Alen’s fire would reduce it all to ash, to blow away in the morning wind, and fall like gray snow on my sidewalk. A patrol of Van Alen’s rainbow guard marched around the fire-stand, toting hunks of charred, nail-studded wood: the signature weapon of the standing army of the Upper West. Passing under the fire-stand, I caught a lungful of sawdust and went into a coughing fit that nearly knocked me down. One of the guardsmen, a slender young man with jagged teeth and an elaborate moustache, took my arm. I took it right back.

“Follow me, ma’am,” he said.

“Absolutely not,” I said, stifling another racking cough.

“You’ll have to follow me.”

Eight men with clubs blocked my path north. Behind me, the humiliated, furious chief of the Gophers. To my left, the fire-stand, to my right, a few hundred yards of broken glass. With no real choice, I followed him, and in the pocket of my dress, I gripped my little knife. The guardhouse was a long wooden structure that spilled into the street. It smelled like salted meat. He held the door open for me.

“On no account,” I said, “will I be joining you in there.”

“Then if you would perhaps wait here? This will only take a moment.”