Mitch frowned. The girl glanced up from her notes. "What's-"

Then it came. A dull booming roar that rattled the windows and shook the house.

"Not another raid!" she whimpered.

"It doesn't sound like-"

Letters began splashing across the screen. EMERGENCY ADVICE TO SARQUIST. MY CIVILIAN DEFENSE CO-ORDINATOR HAS BEEN DESTROYED. MY ANTIAIRCRAFT COORDINATOR HAS BEEN DESTROYED. ADVISE, PLEASE.

"What happened?^"

"Frank Ferris!" he barked suddenly. "The Sugarton crowd-with their dynamite! They got into the city."

CENTRAL FROM SARQUIST, he typed. WHERE ARE THE DAMAGED COORDINATORS LOCATED?

UNDERGROUND VAULT AT MAP COORDINATES K-81.

"Outside the city," he breathed. "They haven't got to the main tanks yet. We've got a little time."

PROCEED WITH ORDINANCE LISTING, he commanded.

Half an hour later they were finished. Then he began the long task of relisting each ordinance number and typing after it: REPEALED; CITY EVACUATED.

"I hear gunshots," Marta interrupted. She went to the window to peer up and down the dimly lighted streets.

Mitch worked grimly. It would take them a couple of hours to get into the heart of the city, unless they knew how to capture a robot vehicle and make it serve them. But with enough men and enough guns, they would wreck subunits until Central withdrew. Then they could walk freely into the heart of the city and wreck the main coordinators, with a consequent cessation of all city services. Then they would be free to pillage, to make a mechanical graveyard of the city that awaited the return of man.

"They're coming down this street, I think," she called.

"Then turn out all the lights!" he snapped, "and keep quiet." "They'll see all the cops out in the street. They'll wonder why."

He worked frantically to get all the codes out of the machine before the Sugarton crowd came past. He was destroying its duties, its habit patterns, its normal functions. When he was finished it would stand by helplessly and let Ferris's gang wreak their havoc, unless he could replace the voided ordinances with new, more practical ones.

"Aren't you finished yet?" she called. "They're a couple of blocks away. The cops have quit fighting, but the men are still shooting them."

"I'm finished now!" He began rattling the keyboard frantically.

SUPPLEMENTAL ORDINANCES: #1: THERE IS NO LIMIT OF SUBUNIT EXPENDITURE.

YOU WILL NOT PHYSICALLY INJURE ANY HUMAN BEING, EXCEPT IN DEFENSE OF CENTRAL COORDINATOR UNITS.

ALL MECHANICAL TRAFFIC WILL BE CLEARED FROM THE STREETS IMMEDIATELY.

YOU WILL DEFEND CENTRAL COORDINATORS AT ALL COSTS.

THE HUMAN LISTED IN YOUR MEMORY UNITS UNDER THE NAME `WILLIE JESSER" WILL BE ALLOWED ACCESS TO CENTRAL DATA WITHOUT CHALLENGE.

TO THE LIMIT OF YOUR ABILITY YOU WILL SET YOUR OWN TASKS IN PURSUANCE OF THE GOAL: TO KEEP THE CITY'S SERVICES INTACT AND IN GOOD REPAIR, READY FOR HUMAN USAGE.

YOU WILL APPREHEND HUMANS ENGAGED IN ARSON, GRAND THEFT, OR PHYSICAL VIOLENCE AND EJECT THEM SUMMARILY FROM THE CITY.

YOU WILL OFFER YOUR SERVICES TO PROTECT THE PERSON OF WILLIE JESSER.

"They're here!" shouted the girl. "They're coming up the walk!"

– AND WILL ASSIST HIM IN THE TASK OF RENOVATING THE CITY, TOGETHER WITH SUCH PERSONS AS ARE WILLING TO HELP REBUILD.

The girl was shaking him. "They're here, I tell you!"

Mitch punched a button labeled "commit to data," and the screen went blank. He leaned back and grinned at her. There was a sound of shouting in the street, and someone was beating at the door.

Then the skaters came rolling in a tide of sound two blocks away. The shouting died, and there were several bursts of gunfire. But the skaters came on, and the shouting grew frantic.

She muttered: "Now we're in for it."

But Mitch just grinned at her and lit a cigarette. Fifty men couldn't stand for long against a couple of thousand subunits who now had no expenditure limit.

He typed one last instruction into the unit. WHEN THE PLUNDERERS ARE TAKEN PRISONER, OFFER THEM THIS CHOICE: STAY AND HELP REBUILD, OR KEEP AWAY FROM THE CITY.

From now on, there weren't going to be any nonparticipators.

Mitch closed down the unit and went out to watch the waning fight.

A bigger job was ahead.

Walter M. Miller Jr grew up in the American south. He enlisted in the Army Air Corps a month after Pearl Harbor and spent most of the war as a radio operator and gunner, participating in fifty five combat sorties over Italy and the Balkans, including the assault on Monte Cassino. After the war he studied engineering before turning to writing. A Canticle for Leibowitz won a Hugo, and his only other novel, Leibowitz and the Wild Horsewoman was published posthumously.