At one point Ramon’s uncle looked over and called irritably to them, “Please! Neatly! Have some pride in your work.”

“Sí, patrón!” the men said, bobbing their heads nervously. Country boys, with the habit of obeisance to authority. And yet Ramon’s uncle was not their boss. But none would cross him.

The fat man had finished with the dead. Now he was dragging one of the live men off the truck. The prisoner was very hairy, and he screamed and squirmed continuously . . . until, as he fell from the truck, the back of his head bounced off the pavement with a sharp crack. It was an awful sound, but then for a moment the plaza went blessedly quiet. Ramon heard only the whir of the hovering bird. It sounded ominous now, and horrible, like the sound of some machine-beetle designed by American military scientists, ready to drill its beak into Ramon’s body and feed.

The stunned man who lay on the ground stirred, then moaned. His hands and feet were bound with heavy black zip ties. The fat Zeta dragged him over to the work area. Chunk! went the spadelike tool. The man’s body went limp as his head flopped off.

Blood gushed out for a moment, then ceased. The dead man’s eyes stared unblinkingly at the sky.

This work was easier on the dead.

In the distance, Ramon heard a thin whine. For a moment he thought it was another hummingbird, perhaps a flock of them.

But then he realized it was a siren. First one, then another, then another.

His uncle heard it, too. He glanced at his watch—it was an elegant and thin timepiece, to which his uncle had given a fancy foreign name, “Patek Philippe”—and scowled. “The lesson here, Ramon? Never trust a policeman. They were supposed to wait until seven thirty sharp. You see what time it is?” He held out the watch on his thin brown wrist. “Seven oh nine.” He shook his head in disgust. “Incompetence.”

“We should go then,” said Ramon, trying not to sound too eager.

Ramon’s uncle neither agreed nor disagreed, turning instead to watch the fat man decapitate another prisoner. One more to go.

Ramon’s uncle called to the fat man. “Bring that last one over here, Carlito.”

Ramon shuddered. He wished the sirens would speed up.

The executioner dragged the final prisoner over to Ramon’s uncle, dropping his legs there. Up close, Carlito was even more powerful in appearance. Even with a custom tool, it took strength to chop off men’s heads.

Ramon’s uncle nodded toward the spadelike tool. He said, “Give the blade to my nephew, Carlito. The time has come for him to see what this business is all about.”

Ramon’s uncle’s life had always seemed romantic and exciting. His estate, his fine things, his commanding attitude. Just being in his presence was seductive.

But now that he had seen his uncle’s work up close, Ramon felt sickened. His uncle, he knew, was not paid by the head. The job was already completed. This was more of a flourish. And Ramon had seen quite enough already, thank you.

But before Ramon could think of an honorable way to protest, the fat man shoved the tool into his hand. Extremely heavy, the wooden handle smooth and worn from having seen so much use. Its crude fan-shaped blade dripped blood onto the ground.

“I made this tool with my own hands,” Ramon’s uncle said. “Mesquite wood. Very tough. And the blade was hand-forged from steel from an excavator tooth. A Caterpillar 321, if I’m not mistaken. American steel, the highest quality.”

Ramon held in his hand the weapon that had beheaded dozens of men. “What is it called?” asked Ramon, stalling desperately.

Ramon’s uncle eyed him, shaking his head. “It has no name.”

The last prisoner rolled from side to side on the ground, his flex-cuffed hands covering his crotch. He was a thin, hairless young man, not many years older than Ramon himself. He had pure Indian features. And all Ramon could think, looking at him, was: Why do you not scream?

The prisoner just stared up at Ramon, his eyes dark and frightened . . . and yet he did not break Ramon’s gaze.

Ramon’s uncle motioned with his hand, a precise downward motion. “Let the weight of the thing do the work. Half of the job is just lifting it up and dropping it.”

Ramon said, “What is the other half?”

“The muscle this task requires is not mere body strength. You must commit to the act. You must drive the blade down and make sure it finds its mark. The thing knows its job. If you do it carefully, and decisively, the thing will do its job kindly. Otherwise . . .”

“Otherwise?” asked Ramon.

“Otherwise you will bungle the job, and try again. Do not take many hacks where one is sufficient.”

The sirens were getting louder. Ramon knew he did not have much time. He also knew he did not want to do this. And he knew that his uncle knew.

“Now is your time,” said his uncle, the brim of his ball cap shading his penetrating eyes. “This tool is a special object. It will find you out. It will do the command not of your grip, but of your will. Of your commitment.”

The tiny hummingbird flew between them, zipping right, then darting away, heading in an upward arc toward a long row of palm trees on the far side of the plaza.

Ramon’s uncle said, “Do you see? Even our little friend knows. It is time to go.”

Then his uncle turned, made a circle in the air with his hands, and began walking away. Suddenly the Zetas around the plaza weren’t lounging anymore. Everyone stood and began sprinting for their trucks: two armored Humvees, an Escalade, and a Ford pickup with a heavy tube frame welded to the back, on which was mounted a belt-fed machine gun.

The fat man, however, stayed with Ramon. He stared at him with black, expressionless eyes. “Come on, you little pendejo. Get it over with. Your uncle is not someone you want to disappoint.”

Ramon looked into the face of the decapitator. He saw pleasure there. “Leave me.”

“You can’t do it.”

“Leave me now,” Ramon said. “I’ll do it. And then I will tell my uncle how you doubted me.”

The fat man shrugged, but didn’t give up on taunting Ramon with his eyes. He walked back to the big GMC and started closing the gate to the bed, obstructing Ramon’s view of the litter of heads lying there.

What had become of his world? Ramon felt his entire body trembling. His armpits and face were slick with sweat, even though the sun was barely higher than the buildings at the edge of the square.

He was aware of the eyes of the man at his feet, looking up at him. Ramon did not look down.

He had to do it. He had to. If he didn’t kill this man, his uncle would never respect him.

Or worse.

Let the weight of the thing do the work. That’s what his uncle said. Whether he was referring to the weight of the object or the psychological measure of the act, it was all the same. If Ramon could just let the weight of the thing do the work, he would not have to get involved at all.

His hands would be clean. And it would be done with.

“You don’t have to,” came the voice.

Not Ramon’s own voice. The young man’s beneath him.

“No one will care if you don’t.”

“Shut up!” said Ramon, kicking his bare shoulder.

The sirens grew closer. Ramon felt eyes on him, real or imagined. The eyes of his uncle, the eyes of the dead, the eyes of the fat, taunting Carlito . . . and the eyes of the young man at his feet.

In that single moment, Ramon could see his entire life ahead of him. Why had he ever wanted this? He had not been forced into it. He had sought it. His older brother was a simple farmer like their father. His younger brother was going to the military school in Mexico City.

There was no need for this, he realized. There never had been.

“This is insane,” said the young man on the ground. “You see that, can’t you?”

Yes. Maybe it was. But perhaps it came to this: Who would Ramon rather be in this insane situation, the man at his feet, or the man wielding the blade?