On September 1, 2178, the QFIC issued Monetary Transition Directive 2178-01, declaring that all physical currency — paper bills, metal coins, polymer notes, and any other form of tangible money — would cease to be legal tender in QFIC-administered territories effective October 1, 2178. Thirty days. The world had thirty days to convert every physical piece of money in existence to Quanta or watch it become worthless. The Directive called it "monetary modernization." The people who lived through it called it the Great Conversion, and for many of them, it was the day money died.

The logistics were staggering. In GLMZ alone, an estimated $2.3 billion in physical currency was in circulation — not counting the unknown quantities hidden in mattresses, buried in yards, and locked in safes by people who trusted the weight of bills more than the promises of institutions. Conversion centers were established at every transit hub, every government office, and every corponation administrative center. The conversion rate was fixed at the prevailing Quanta exchange rate on September 1: $1.00 = Φ0.178. A lifetime of savings that felt like $10,000 became Φ1,780. The number was correct. It felt like robbery.

The lines were the defining image of the Great Conversion. At the main conversion center in what is now the Financial District, the line stretched 2.3 kilometers and the wait time exceeded 14 hours. People brought lawn chairs, food, entertainment. They brought their money in shoeboxes, in duffel bags, in their pockets. An elderly woman brought a suitcase containing $180,000 in bills — her life savings, accumulated over sixty years of work, stored in her apartment because she did not trust banks. The conversion staff counted it by hand. It took three hours. She received Φ32,040. She stood in the center, surrounded by machines and screens and people in uniforms, holding a receipt for a number she could not touch, and she wept. She was not the only one.

The people who suffered most were those on the margins — the unbanked, the undocumented, the cash-dependent populations who operated entirely outside the digital financial system. For them, the Great Conversion was not a transition. It was an extinction event. An undocumented worker with $4,000 in cash could not walk into a conversion center because conversion required identity verification, and identity verification required documentation they did not have. A street vendor whose entire business ran on cash faced a choice: convert and be counted, or don't convert and lose everything. The QFIC established "no-documentation conversion" stations in the final week, allowing identity-free conversion for amounts under $500 — a concession that addressed the political optics while leaving the structural problem intact. If you had $5,000 and no papers, you could convert $500 and watch $4,500 become paper.

After October 1, the physical money was destroyed. Incinerated, shredded, melted — depending on the material. The ash was used as aggregate in construction material. The metal was recycled. Somewhere in the walls of GLMZ, in the concrete and the steel and the composite panels, there are trace elements of every dollar and every coin that the people of this city ever held. The money is in the walls now. You cannot spend it. You cannot hold it. But it is there, atoms of copper and zinc and cotton fiber, embedded in the infrastructure of a city that runs on numbers that no one can touch. The Great Conversion succeeded. Everyone has Quanta now. Everyone has a number. And the money — the real money, the money that had weight and texture and history — is in the walls, and no one remembers what it felt like except the people who are dying, and they cannot make the young understand what was lost, because the young have never held anything in their hands that the system could not take away.