«They're coming,» Rosa said. She was out of breath, and Alex watched her put one hand on the door frame to steady herself.

So much for hope, Alex thought. «They've left San Miguel?»

«They're leaving now. I just got off the phone with Gabi. She thinks four, maybe five hundred of them.»

Diego had been nodding off at his desk in the corner, flat cap pulled low until his grizzled beard was all that showed, perpetually empty pipe still in his mouth. He was awake now. «Dios mío,» he said, and he crossed himself.

It was 11:18 Wednesday morning. «It'll take them five or six hours to get here,» Alex said, «and then they'll probably wait until the middle of the night to make their move. We've got twelve hours, if we're lucky.» He switched to email and sent a one-word code to the Guardia list.

«The cuernos?» Diego asked.

Alex nodded. To Rosa he said, «Get on the radio and call a town meeting for two o'clock.»

Rosa was in her late forties, fifteen years younger than either Alex or Diego. Her intense, close-set eyes had gone bloodshot. «Ay, Alejandro . . .»

«At least this way the waiting's over. ¿No?»

Alex waited at the storeroom for Diego, who was struggling in the relentless heat. He unlocked the door that led to a stone-walled room, a rough table, and a second door. Then he locked the first door behind them and unlocked and opened the second.

A square of cardboard was tacked to the back of the second door, painted street-sign green, with white letters that read "Desolation Row." It was the name of the Dylan song whose jaded cleverness had defined him in high school. The sign reminded him that he'd once had a sense of humor.

The crates along the left-hand wall were long and narrow, like children's coffins. Each one held ten AK-47s, disassembled and wrapped in greasy rags. Cuernos de chivo, the locals called them, because the curved clip looked like the horn of a goat. Alex, Diego, and Rosa were the only people in Mexico who knew these guns existed.

Cubical boxes on the right-hand wall held ten thousand rounds of old-style 7.62x39mm ammo. The other crates contained dynamite, plastic explosive, fuses and detonators. Alex had long ago decided that if it came down to it, he was not going to screw around.

Together they carried a crate to the table. Alex pulled off the loose board at the top and exposed the dull gray-green metal of a rifle barrel poking out of a rag. He thought his periodic checks had inured him, but today his stomach lurched at the sight.

«Can we talk about this?» Diego asked.

«We've talked. Passive resistance means my people raped, murdered, tortured.»

«So we're not pacifists anymore?» Diego shrugged apologetically. «I don't know how I'm going to explain this.»

«There's no name for what we are. We're making it up as we go along. Please, just get started. I'll send you some help soon. You've got your keys?»

Diego held up his key ring and said, «Go with God.»

Alex stopped at the top of the stairs for one last look at the Chávez Morado "Abolition of Slavery" mural, the reds and browns and oranges, the flames, the skeletal bodies, the carrion birds. Let it still be here tomorrow, he thought.

On the street, he breathed the hot, still air of Guanajuato. It was early May, the hottest month in the central mountains, hotter every year now, as each year the rains that were supposed to come between June and September were more erratic, less able to settle the dust of the long, dry spring.

The city lay in a natural bowl, surrounded by hills, the houses crowded onto the steep slopes like giant sugar cubes, white and mustard yellow and pastel pink and green and blue. Higher up were the eight commercial-scale wind turbines, two megawatts each, that Alex had used to buy the loyalty of the locals and bind the community together. The turbines had cost him everything he'd inherited from his father, everything he'd worked a lifetime for, every dollar contributed by the investors who had followed him down from the States, every penny he'd borrowed knowing he would never pay it back.

It was the most naturally defensible city he'd ever seen, complete with a network of tunnels underneath the city center wide enough for two-way traffic. He'd been born in Dallas, but his father was a Guanajuato native and the family had spent every Christmas here while Alex was growing up. Now he had his own personal fortress in the middle of it, La Alhóndiga de Granaditas, the former grain warehouse that had been the last refuge of the Spanish in Guanajuato when the 1810 Revolution started, the Revolution that Chávez Morado had celebrated in his mural, the Revolution whose principles had gradually eroded away, like everything else in the world, under the relentless need of the doomed and desperate human race.

He grabbed a yellow bicycle from the rack. The nearest set of steps that led up to the Pípila statue were halfway across town, fifteen blocks away. The statue was the highest point in the city, and the hundred or so members of Alex's handpicked "neighborhood watch" patrols would be making their way there now, not yet knowing the real work he'd chosen them for.

Word of the invasion had already spread. Shutters were rolling down over shop windows and doors, and vendors were streaming out of the two-story Market building at the foot of the hill. People stared at him anxiously as he pedaled past. The streets were full of yellow bikes and he made a mental note to have Rosa get them rounded up and inside La Alhóndiga by nightfall. One more detail . . .

He parked at the mouth of the alley that started the uphill climb to El Pípila. As he tried to fill his lungs with thin mountain air, he saw one of the squad leaders jog toward him. Billy was in his mid-twenties, born and raised in Guanajuato, with bleached yellow hair, a ring through his left ear, a Che T-shirt, and Velcro-pocket hiking shorts. He'd been a bank teller, a street performer, and a bouncer, and he'd also spent two years in the US at a private security firm. Alex considered him loyal but unstable. He also believed that a stable person might not be able to pull a trigger.

«¿Qué onda, Alex?» Billy said. His fear was obvious in the high, nervous pitch of his voice. «Is this the real thing, like they're saying?»

Billy wasn't the touchy-feely type, so Alex didn't offer his hand. They turned together and climbed the narrow steps between two white stucco houses. «Yeah,» Alex said. «Los Zetas.»

«They're going to kill us all,» Billy said.

Alex made himself slow down, already feeling the steepness in his sixty-three-year-old legs and lungs. «Maybe not,» he said. «I have a surprise for you.»

An hour later he was back in the city center, at the Plaza Allende next to the Teatro Cervantes. It had gone well with the new militia and they'd cheered when he told them about the guns. From the start he'd recruited men and women who not only had long histories in the city but also had kinship ties to each other—an army of brothers and sisters and cousins and in-laws. They understood that everything depended on secrecy and accepted his orders that the squads stay together until Los Zetas arrived, keeping an eye on each other and not talking to anyone outside the group.

Now came the hard part. He'd asked Rosa to do it and she'd refused, saying this lie was on his head, not hers.

He got up on the permanent stage in front of the statues of Quixote and Sancho Panza. He was looking at close to fifteen hundred people, a good ten percent of the city's shrunken population. The city's five hundred or so gringos were particularly well represented.

Alex stepped up to the microphone and amp, borrowed from a local rock band, and started talking. He tried to project calm as he ran down the basic facts, leaving out the part about the guns.

«I want all of you to barricade yourselves in your houses and turn off all the lights. If you don't feel secure in your house, come to La Alhóndiga. If you've got small children, bring them to La Alhóndiga. Try and get anything of value off the streets. If you have a booth at el Mercado, bring everything home.»

People shouted questions as Alex plowed ahead. «If you want to leave the city, we'll keep the Valenciana tunnel open until seven p.m. You're welcome to come back when this is over.»

One of the gringos at the foot of the stage was shouting in English. "Are you not going to do anything to defend us?"

«Everyone here,» Alex said, «is supposed to have signed the compact that pledged us to nonviolence.» He felt like an imposter, piling lies on top of the blatant violation of his own code that was already in progress. «We knew there would be a test sooner or later. This is it. If you've got some kind of weapon hidden away and are thinking of using it, don't. You will only escalate a very grave situation and endanger yourself.

«We'll broadcast updates as soon as we know anything.» His voice was drowned in shouted questions. «Be strong,» he said, and turned away.

Hands reached for him as he made his way through the crowd. He put on a false smile and nodded and kept moving.

By nine that night everything was in place.

Years ago they had closed all but two of the roads into the city with dynamite, rockslides, or cinder block walls. The two surviving roads ran through tunnels under the mountains, one in the southeast by Plaza Pozuelos, the other in the northwest, leading to Valenciana. The entrances were blocked by wooden barricades and guarded by volunteers armed only with cell phones.

Webcams gave Alex a panoramic view of the outside road that led to the Pozuelos entrance. The south-facing cameras registered a glow on the horizon where Los Zetas were marshalling their attack. His informants had mentioned Hummers, motorcycles, balloon-tired ATVs, and a pair of 18-wheelers full of weapons. Alex had no idea where they stole their gasoline—there hadn't been any in Guanajuato in years.

His two kids and his younger brother and their extended families were all still in the States. He'd tried to bring them along when he moved to Mexico but they'd been too afraid. Now that the US had disintegrated, there was no way to get them here. Air travel was by private jet only, and the border was a war zone. The rich in the US had enough gas to drive in and out of their Green Zones, much like Los Zetas and the other cartels here, with their SUVs and armed escorts, their fresh beef and imported liquor. The rest, like Alex's family, survived however they could.

Each passing minute twisted Alex's nerves tighter, like an over-tuned guitar string.

He had three squads of ten soldiers each in trenches and abandoned houses above the mouth of the tunnel that led into the city. Every twenty or thirty minutes one of them would call, asking what was happening, though Alex had asked them to keep the line clear.

At midnight all three squads called in succession. They could hear engines in the distance. One said it sounded like the ocean, another that it was more of a vibration deep in the ground.

The first headlights crawled over the crest of a hill, still two or three miles away, flickering like fireflies. Alex was exhausted, sick, afraid, wishing he were anyplace else.

Ten minutes later, the lead Hummer took out the abandoned barricades as if they were popsicle sticks. A convoy of motorcycles rode in its wake. Then pickup trucks, with men packed into the beds like bundles of asparagus.

Alex kept a line open to Diego, waiting on the mountainside above the tunnel. When? Alex asked himself. The tunnel was maybe a thousand yards long. How many do I let in, how many do I leave outside? The first Zetas were already through and on the city streets.

The 18-wheeler made up his mind. As soon as the trailer was completely inside the tunnel, he said, «Now!»

There was an agonizing delay. Then cameras on both sides of the tunnel went yellow-white as the explosives went off, the noise too loud to come across as anything but static. Then, unexpectedly, the outside entrance erupted again, and again, and there was a rattling like popcorn in a microwave as the heat set off the rest of the ammo in the truck.

Alex heard cheering on the other end of the phone. «Shut them up,» he said, «and tell them to keep down. No firing until my signal.»

The cameras on the city side of the collapsed tunnel showed swirling dust and headlights, vehicles swerving around, silhouettes conferring, pointing, shouting into phones. Finally the remains of the convoy started down into the city.

Alex tracked them via webcam as they drove past the other two main defensible or lootable structures, the University and the Market, and found the doors propped open and the buildings empty. They conferred again, and pointed the lead trucks toward La Alhóndiga.

«Take over,» Alex said to Rosa. «I'm going upstairs.»

Billy's squad was one of four on the roof. Alex had thought it best to keep him close. There was another monitor there, with a split-screen view from webcams on all four sides of La Alhóndiga. Alex used it to watch Los Zetas form up on the intersecting streets outside the only two doors into the building, at least a hundred of them, maybe more.

His throat was so tight he wasn't sure he'd be able to talk.

A man opened the driver door of the lead Hummer and leaned out. He had two days' growth of beard, a bandana holding back his long hair, and a pair of goggles. «Órale, what the fuck?» His voice was clearly audible on the roof. «I thought you guys was supposed to be pacifistas? I think you might have made us a little mad. You should open up these doors, because we don't really want to burn up anything useful. But you need to do it really fast.»

Two teams of Zetas had rocket-propelled grenades aimed at the thin metal doors of La Alhóndiga.

Alex had a speech ready, offering them the chance to leave through the Valenciana tunnel, promising none of them would be hurt, etc. In the moment it seemed like pointless bullshit.

The squad leaders were all looking at him. He picked up his phone, so the squads above Pozuelos would get the order at the same time. Then he held up his right arm and swung it down in the general direction of the lead Hummer.

«Rocket launchers first,» he said. «And then . . . mátalos a todos. Kill them all.»

His soldiers moved to the edge of the roof and opened fire.

When the worst was over, he went downstairs. The interior courtyard and balconies churned with people. Voices called to him as he pushed his way through, asking about the gunshots. «Everything's okay,» he said.

They followed him to the room that held the radio station. A small crowd had gathered around the one-watt FM transmitter that he'd liberated from the University, and someone was offering what she knew about Los Zetas on the air. She stopped when she saw Alex and gave him her chair.

He took a second to focus, then said, «This is Alex. The first thing I have to tell you is that I lied when I said no firearms would be tolerated in Guanajuato. . . .»

Sporadic gunshots continued through the night while Alex dozed at his desk. At dawn on Thursday, the militia made a sweep of the streets and the tunnels under the city and gathered up the stragglers. Alex guessed at a hundred and fifty Zetas dead, not counting the ones who'd died or were still dying in the Pozuelos tunnel. Another hundred wounded and fifty or so prisoners.

Alex had lost three people: one on the roof Wednesday night and two more on the streets the next morning, one of those to "friendly fire." He had a dozen wounded, most of the wounds minor.

The Zetas who'd been outside the tunnel when it blew had taken heavy casualties from the squads in the hills. They'd pulled back and were apparently waiting to see what came next.

As the adrenaline wore off, Alex's soldiers began to sag with exhaustion. He called for volunteers for the cleanup and kept working, needing to finish it. Though he'd ordered everyone to stay home who wasn't helping out, there were already protesters, mostly Anglos, who got as close as the soldiers would let them and shouted at him for his betrayal. Alex could think of nothing to say in return.

They loaded the dead Zetas in the vehicles that still ran and drove them through the Valenciana tunnel to a flat spot in the desert. The heat there was staggering, the winds fierce and laden with stinging sand particles. The workers, in bandanas and baseball caps, quickly turned the color of the eroding soil.

They made additional trips for the wounded and the prisoners, and to tow away the disabled vehicles. With a pang, Alex ordered all the motorcycles driven or towed to the site as well. There was resistance, finally, over this, and prolonged grumbling.

They poured gasoline over the pile of corpses and trucks and motorbikes, and while the surviving Zetas watched from a distance, Billy started the conflagration with a captured rocket launcher.

They left Los Zetas there, the living and the burning, and retreated to the city. The barricades went up again in the tunnel. Diego and Rosa collected the cuernos de chivo while Alex watched, nodding in and out of sleep. The guns went into the now overflowing arms closet next to the weapons they'd confiscated from Los Zetas. There would be time to clean them and pack them away later.

Finally Alex told Rosa to broadcast the all-clear.

He went up to the roof alone and watched as the sun set and an old woman scrubbed blood from the sidewalk in front of her house with a brush and a chipped enamel basin of murky water. Then he went to bed and fell asleep under his slowly turning ceiling fan as the noise of the celebrating city echoed around him.

Rosa arrived in time for lunch on Friday. They sat together at the table in the gleaming stainless-steel kitchen. «Give it to me,» Alex said.

«Lots of serious drinking, as you would expect. A few drunken fights, mostly started by angry pacifists. Nobody got hurt too bad. Two more Zetas turned up, hiding in the tunnels downtown. The cops took them away before they could be lynched.» Rosa hesitated.

«And . . . ?»

«Two rapes,» she said.

«Christ. Soldiers?»

«Yes. One of them was three on one. It got rough.»

«Do they have the guys who did it?»

«We picked them up this morning, quietly, took them to jail in a closed rickshaw. But there's going to be trouble. These guys think they're heroes now. They think the city owes them.»

Alex leaned back heavily in his chair. When he'd arrived nine years before, carrying one suitcase full of plans and another full of cash, Rosa had been the newly elected mayor of a dying city. The drug cartels, de facto government of half the states in Mexico, had scared off the Northamerican tourists who had provided most of Guanajuato's income. The rest had come from students at the University, only no one could afford to study anymore, not since rising sea levels had emptied the coastal cities and crashing economies had wiped out bank accounts all over the planet. Three quarters of the population had left in hopes of tech jobs in Guadalajara or auto work in San Luis Potosí, or for the ever more nebulous dream of crossing the border into an ever more chaotic US. Officially Rosa was still the mayor, still the voice of the government, only now Alex paid half her salary in exchange for being her mostly silent partner.

«So where are they drinking?» Alex asked.

«The Santa Fe was the place last night.»

It was the hotel bar in el Jardín de la Union, the main square. There weren't many other bars left that could hold a crowd. «Okay,» Alex said. «I'll check it out tonight.»

«Be careful. Has abierto la caja de los truenos.» You've opened the box of thunder. «You can't put it back inside.»

Trueno also meant gunshot, giving the proverb added sting. «I know,» Alex said.

«There is one piece of good news. Los Zetas have moved on. For now.»

Alex waved his hand. «They moved on. Let's settle for that.»

The manager of the Santa Fe put Alex in a closed-off balcony where he could see the main floor of the bar from darkness. At a long table near the bar, Billy had the attention of thirty or more admirers, a mixture of fellow veterans and civilians, including a couple of women beautiful enough to make Alex's aged heart ache.

«Never felt anything like it,» Billy was saying. «It was better than sex, better than kicking a goal in overtime, even. It was power, man, sheer, raw power. You pull the trigger, you feel the heat blasting out behind you on the skin of your back, then you see the trail of the rocket, it almost looks wobbly going up, and then whoosh, ka-booooom!»

«Kaboom and adios motorcycles,» said one of the soldiers bitterly.

«Well, most of them, anyway,» Billy said. «You can't let fuck-brained politicians make all the decisions, no?» He'd been into the tequila. He wasn't slurring his words, but his voice kept rising.

«Speaking of which,» another soldier said, «what about 'Litos and them?»

«We're getting them out, don't worry. Just show up at the rally tomorrow. And bring everyone you can, but keep it quiet, right? Word of mouth only.»

«What rally?» somebody else asked.

«Just, we need to make a few adjustments. First Alex and them lied to us about the guns, and now they want to pretend like what happened didn't happen. But it did happen, and we're not going to be victims anymore.»

Alex slipped out and walked home. The night was hazy and too hot for decent sleep. Alex knew that he couldn't actually see the methane that was boiling up out of the Russian tundra, or the monoxide from Los Zetas' engines, or the smoke from the tires that burned all across the African continent. Still, it felt like a long time since he'd seen the stars.

Back in his room he put on Bob Dylan. Right now, the singer said, he couldn't read too well. He said, Don't send any more letters, not until you spend some time in the world I'm living in now.

He was a long time getting to sleep.

At least two hundred people had already shown up in Plaza Allende, with more coming. At high noon the temperature was well over 100. Somebody had hung a banner across the Quixote statue that read VIVAN LOS HEROES, and, God help them, a huge Mexican flag above that.

Billy and three other squad leaders were working themselves up in the ramada to the left of the stage. They'd put together uniforms of a sort, khaki pants, white T-shirts, and green caps with the logo of the Mexican fútbol team.

All four had AKs on their shoulders and sidearms on their hips.

Finally they started toward the steps that led to the rear of the stage. Alex had to move quickly to cut them off. The audience was already clapping and cheering. He stood on the bottom step and faced them. His heart pounded and his hands shook, not at all the effect he wanted.

«Alex,» Billy said with a nod. «You need to step aside.»

«I can't do that,» Alex said. He thought about the way his father used to control him through sheer willpower, even after Alex was bigger and stronger.

Billy looked to his right, at the swelling crowd. Their energy, their raised fists and shouts, electrified him.

«I mean it,» Billy said. «If you don't get down, we'll take you down.»

«And I'll fight back,» Alex said. They were far enough from the spectators not to be overheard, but were clearly visible. «You won't look very heroic, beating up an old man.»

Billy took out his pistol. It was a Glock 9mm, a favorite of police and criminals everywhere. It was the move Alex had hoped he would make. The gun was a corner, and Billy had backed himself into it.

«I don't have to lay a finger on you,» Billy said.

«No,» Alex said. «But you are going to have to kill me.»

He saw with relief that Billy had not anticipated this moment.

«I'm unarmed,» Alex said, «and I'm not threatening you. There are a couple of hundred people watching.»

Billy licked his lips.

«It's different now,» Alex said, «isn't it? I came to your girlfriend's house when I asked you to join the Guardia. I petted your dog. Can you do it? Can you shoot me down just because I don't agree with you?»

The crowd had realized that Alex was not there to put garlands on the centurions. There was a low hum of questions.

Billy shoved the gun in its holster and looked at his lieutenants. «Get him out of the way.»

Alex's hands had stopped shaking. «Hola, Pablo. Inés, how's your mother? Sergio, did you get over that cough?» All three looked away and remained where they stood.

Alex said, «You're going to have to do it yourself, Billy. I honestly don't care that much. Because if we have a standing army here, then we are already headed down the same road as every other government that failed. We can't let people commit murder for a living, or call them heroes for it, because then the killing never stops. I don't care about myself, I haven't got that much longer anyway. The thing is, the way we're dying off, there's eventually going to be a population small enough for the planet to support again. I would like some things to survive. The murals in La Alhóndiga. Bob Dylan. Books. People who can read them.»

«You're a fucking hypocrite,» Billy said. «Violence is fine when you say it's okay. Then you want to turn it off like a faucet. Life is fucking miserable here, and Los Zetas have things that could make it better. They owe us. And if we don't finish them now, they'll be back.»

«It's not fine,» Alex said. «It's never fine. No matter which side of the gun you're on. That's the point.»

Somebody moved in his peripheral vision. It was Rosa, and apparently she'd been listening. «You'll have to kill me too, I'm afraid.»

Diego was with her, and he got up on the step next to Alex. «Me too,» he said. «And many, many more.»

Billy had gotten a trapped-animal look around the eyes.

«You have to turn in the guns, Billy,» Alex said gently. «And the motorcycles. And anything else you took from Los Zetas.»

«Or what?»

Alex took a deep breath. «Or leave.»

The crowd had come for a speech, so Rosa gave them one. It only lasted five minutes. It talked about corpses piled in their streets, the violence that violence breeds, the desire they all had to return to the way things had been before the attack. As she talked, the light slowly went out of Billy's eyes.

When she was done, she moved through the audience, touching shoulders, saying a few words, and by the time she got to Alex, she had a knot of twenty people with her.

Inés and Sergio turned in their guns and went home.

Alex walked Billy and Pablo to the house where they'd hidden two motorcycles. Rosa and her impromptu deputies followed along. Diego went to tell Billy's and Pablo's families. Then Billy and Pablo rolled the silent bikes through the streets as Alex and the others trailed behind. At the Valenciana tunnel, Alex gave them a few minutes to say their goodbyes while Diego took a crew ahead to shift the barriers.

Billy hesitated at the sight of the blowing dust.

«You can change your mind,» Alex said. «Now, a week from now, whenever.»

Billy didn't answer. He and Pablo got on the bikes, settled their AKs across their shoulders, and pulled bandanas over their mouths and noses. They kicked the machines to life and roared away without looking back.

As they walked back through the tunnel, Rosa said, «Los Zetas will welcome them with open arms.»

«I know,» Alex said. «If they don't kill both of them first.»

«There are still guns in the city,» Rosa said. «We can't even guess how many.»

«Rosa,» Alex said, «you can stop now. Please.»

When they came out of the tunnel, the clouds overhead had turned dark. Alex heard the low rumble of distant thunder.