It was the height of the cherry blossoms.

By the time we met for what Moolah had warned would be the slow story, the trees in the park were at their fullest - that brief week of complete saturation when the branches look almost solid white from a distance, and the petals begin to drift in small constant flurries even on still afternoons. The hanami crowd had reached its peak. Tarps everywhere. Children running. Old couples sitting on benches and saying very little to each other. The kind of week, in Tokyo, when the entire city seems to agree, briefly, on what beauty looks like.

We did not go to the bench.

Moolah had asked us to meet at a different place - a small bar she had not previously mentioned, in a quiet alley in Yanaka, three streets from the cemetery. The bar was open in the late afternoon for reasons I did not understand. There were six seats, all empty. The bartender, a woman in her seventies with white hair pulled back into a tight bun, set down three small glasses of barley tea without asking what we wanted. Moolah climbed onto the seat between us and looked at the wall behind the bar for a long moment before speaking.

"I told you last week," she said, "that I lost a friend in May of 2022. I want to start there. Because the story I am about to tell you is not, in the first place, a story about a protocol. It is a story about people, and what happened to them, and what we owe them when we tell what happened. The numbers are spectacular and I will give them to you. But the numbers are not the point. The point is the people. Try to remember that, even when I get to the parts that sound like math."

She took a small sip of barley tea.

"Have you heard of UST?"

"It came up in Episode Four," Dev said. "The algorithmic one. The third kind of stablecoin."

"It came up because I knew we would have to come back. UST - TerraUSD - was the third kind. The kind I told you about with the most caution. The kind that was not backed by dollars in a vault, or by collateral locked in a contract, but by an algorithm and a sister token. The kind I called a chair propped up by promising it can stand. By May of 2022, UST was the third-largest stablecoin in the world. Eighteen billion dollars in circulation. Used by hundreds of thousands of people. Held by funds, by individuals, by small DAOs, by people in countries with broken currencies who had been told it was a safe place to keep dollars. Eighteen billion. And then, over the course of one weekend, it became almost nothing."

She paused. The bartender, behind us, had begun cleaning the same glass for the second time. I had the strong sense she was listening.

"To tell this properly, I need to explain how the system worked. So bear with me."

She arranged the salt and pepper shakers on the bar in front of her, and a small toothpick holder, in a triangle.

"There were two tokens. UST, the stablecoin, was supposed to always be worth one dollar. LUNA, its sister, was a regular volatile token whose price moved with the market. The two were connected by a smart contract that worked like this. At any time, anyone could swap one UST for one dollar's worth of LUNA, and vice versa, no matter what the market price of either was. This was the central mechanism. If UST traded above a dollar, you could mint UST by burning LUNA, sell the UST for more than a dollar, and pocket the difference. The arbitrage would push the price back down. If UST traded below a dollar, you could buy UST cheap, swap it for a dollar of LUNA, sell the LUNA, and pocket the difference. The arbitrage would push the price back up. The two tokens, in theory, would always keep each other in line."

"And in practice?"

"In practice, it worked for a long time. Almost two years. The protocol grew from a small experiment into something enormous, and the people running it became some of the most prominent figures in the industry. They funded a separate protocol called Anchor that paid twenty percent annual interest on UST deposits. Twenty percent. Risk-free, the marketing said. A safe place to park your dollars. People believed it. UST grew to fourteen billion. Then sixteen. Then eighteen. The team began purchasing Bitcoin reserves to back the system as an additional safety net. They bought several billion dollars of Bitcoin. They called the entity holding it the Luna Foundation Guard. They said it would defend the peg in any crisis. People believed that, too."

"What went wrong?"

"What goes wrong with every system that depends on confidence. Confidence wavered."

She rearranged the shakers slightly.

"On Saturday, May seventh, 2022, a series of large UST sales hit the market. We do not know, definitively, who initiated them or whether they were coordinated. There are theories. There has been litigation. The truth has not fully emerged and may not. What is certain is that on that Saturday afternoon, UST traded down to about ninety-eight cents. Below the peg, but only slightly. Within the range of normal fluctuation. The arbitrage mechanism should have kicked in, restored the peg, and the matter would have ended."

"Did it?"

"It did not. Because something else had begun. People who held UST began to notice the price was off. Some of them, remembering that UST was algorithmic rather than fully backed, decided to exit. Not because of any specific failure - only because the small slippage from the peg made them nervous, and a nervous holder of an algorithmic stablecoin is a holder who is very close to selling. They sold. UST traded down further. More holders noticed. More sold. By Sunday, UST was at ninety-five cents. By Monday morning, ninety. The peg had broken. The market began to question whether it could be restored."

I was writing fast. May 2022. UST started slipping. Algorithmic peg requires confidence. Confidence breaking.

"Now," Moolah said, "watch the mechanism."

She moved the salt shaker - the UST - closer to the toothpick holder.

"As UST slipped below a dollar, the arbitrage incentive said: buy UST cheap, swap it for a dollar of LUNA, sell the LUNA for cash. This was supposed to support the peg. But to do this, the protocol had to mint new LUNA out of thin air, every time someone arbitraged. Each redemption created new LUNA tokens that did not previously exist, and those new tokens were sold immediately into the market by the arbitrageurs. So as UST holders panicked and exited through the swap mechanism, the supply of LUNA grew. And grew. And grew. The price of LUNA, which had been around eighty dollars at the start of the week, began to fall as the new supply hit the market."

She moved the toothpick holder downward on the bar - LUNA's price.

"This is where the death spiral begins. As LUNA fell in price, each UST being redeemed required more LUNA to satisfy the swap - because the protocol promised one dollar of LUNA per UST, and a falling LUNA price meant more tokens needed to hit that dollar value. So more LUNA was minted per redemption. Which pushed the price down further. Which meant the next redemption required even more LUNA. Which pushed the price down further still. The mechanism that was supposed to defend UST became the mechanism that was destroying LUNA. And as LUNA's price collapsed, holders began to wonder whether the system as a whole could survive at all, which made them want to exit UST faster, which accelerated the spiral."

Dev was leaning forward. He had been through several minor crashes by now, but never this - never the slow architecture of a stablecoin disintegrating from the inside.

"How fast?"

"Faster than anyone could have imagined. By Wednesday, May eleventh, LUNA had fallen from eighty dollars to about ten. By Thursday, it was under one dollar. By Friday, it was effectively zero. The total market capitalization of LUNA - which had been over forty billion dollars at its peak - was, within a week, less than a few hundred million. Trillions of new LUNA tokens had been minted in those days, attempting to defend the peg. They succeeded only in flooding the market with worthless tokens. UST, in the same period, fell from one dollar to about twelve cents. Holders who tried to redeem at the end received almost nothing. The Luna Foundation Guard's Bitcoin reserves, which were supposed to defend the peg, were spent in the first forty-eight hours and were nowhere near enough. The reserves bought a few hours of stability, but no more."

"Eighteen billion dollars."

"Eighteen billion dollars of UST became less than two billion. Forty billion dollars of LUNA became approximately zero. Total losses across the ecosystem, including the various projects built on top of Terra, are usually estimated at around sixty billion. Some of that was speculative capital that could afford to disappear. Much of it was not. Many who held UST had been told, repeatedly, that it was a safe place to put their savings. Many of them were not in a position to lose what they lost. The damage was global. There were suicides, in the weeks afterward, that are documented. There were many more, almost certainly, that were not. There were people who had put their retirement funds into Anchor at twenty percent yield. There were small-business owners who had bought UST to pay their employees in dollars. There were villages, in some parts of the world, where a meaningful fraction of the local economy had moved into UST because the local currency was failing. All of it. Gone in a week."

The bar was very quiet. The bartender had stopped cleaning the glass.

"My friend," Moolah said, in a voice I had not heard from her before, "had taken a loan from his family to buy UST. He had told them it was safe. He had told them it was simpler than the bank, with better returns. He had been a careful person, mostly, who had read enough to think he understood what he was buying. He did not understand what he was buying. Almost no one did. The marketing material described it as a stablecoin. The mechanism described it as a self-balancing reflexive system that had never been tested in a crisis. He read the marketing material. He did not read the mechanism. By Friday of that week, his family's money was gone. He spent the next year repaying it. He is not the same person he was. He stopped working in the industry. He is, as I told you last week, alive. But there are kinds of being alive that are also kinds of being broken, and that is the kind he became."

I was crying a little. Quietly. The way you cry when the story is not your own but you can feel it close enough.

"What did the industry learn?" I asked, when I could.

"Several things. First - that algorithmic stablecoins are, as a category, structurally fragile in ways their advocates had been minimizing for years. There had been warnings. They had been ignored. Several smaller algorithmic stablecoins had failed before Terra. Each time, the response had been that those projects were poorly designed; the design that finally works will be different. Terra was supposed to be the design that finally worked. It was not. After Terra, the consensus shifted decisively. New algorithmic stablecoins are still attempted, occasionally, but they are smaller, they are warier, and they are watched with much more skepticism. The category has been chastened, possibly permanently."

"And the second?"

"The second is that yield without explanation is poison. Anchor's twenty percent annual yield, paid out in UST, was funded primarily by the project's own treasury - not by genuine economic activity within the protocol. It was, in essence, a marketing expense disguised as a savings account. Users who could not have explained where the yield came from were, in retrospect, paying for it themselves, slowly, as the project burned through its reserves to keep the headline number high. We talked about this in Episode Twelve. Yield you cannot explain in a paragraph is yield you cannot hold safely. Terra was the textbook case. The example I always come back to."

"And the third?"

She was quiet for a moment.

"The third is that trust at scale is not the same thing as trust at a small scale. When a protocol holds a hundred million dollars, the failure of that protocol is bad. When it holds eighteen billion dollars, the failure of that protocol is a different category of event entirely. Lives change. Markets shake. Confidence in adjacent systems is shaken. After Terra, there was a domino effect. Lending firms that had exposure to UST or LUNA failed. Hedge funds that had borrowed against LUNA failed. The contagion took down, by my count, at least a dozen major firms over the following six months. We will be talking about one of them - FTX - in two weeks. FTX would not have collapsed when it did, in the way it did, without Terra. The crisis of 2022 was not a series of independent failures. It was one failure, propagating outward, breaking everything weak enough to be broken. Terra was the first domino. We are still, in some ways, recovering from how it fell."

I had stopped writing. I did not feel like it. The bartender quietly refilled our barley tea.

"Why did this work for two years?" Dev asked, after a long silence. "If it was so fragile?"

"Because confidence is real until it isn't. The mechanism worked as long as redemptions were small and the market was calm. Calm conditions hid the fragility. Many systems are like this. They look stable for a long time, and then they aren't. The architects believed the mechanism was robust. The users believed the architects. The investors believed the marketing. Everyone, in some sense, was believing in each other. And the belief was the only thing holding the system up. When the belief faltered, there was nothing underneath. The chair was, indeed, propped up by promising it could stand. Eventually, somebody who had not been told the story sat down on it. The chair could not stand."

We sat there for a long time. The afternoon light through the bar's small window had begun to fade. Somewhere outside, a child laughed. The cherry petals were still falling. The world was, for everyone except the people who had lost something in May of 2022, a beautiful spring afternoon.

"Same place next week?" Dev asked, after a long while.

"No," Moolah said quietly. "I want a different place. There is a story I need to tell about a bridge that was guarded by exactly five doors, and the people who had keys to all five. Wear walking shoes."

She slipped down from the seat and padded toward the door. The bartender, without saying a word, handed her a small piece of melonpan wrapped in paper. Moolah took it gravely. They nodded at each other. I do not know how long they have known each other. I do not know whether I will ever know.

We paid the bill. We walked home in the long blue twilight. The cherry blossoms continued to fall.

I did not write in the notebook again that night. Some lessons need to settle before they can be written.

Next: Ronin (2022) - When the Guards Were Too Few