At Tio Holtzman’s extravagant house, high on a bluff, Norma Cenva spent three exhilarating days settling into her expansive laboratory space. She had so much to do, so much to learn. Best of all, the Savant was eager to listen to her ideas. She couldn’t have asked for more.

Quiet Poritrin seemed so different from the dense, dangerous jungles and lava-rock canyons of Rossak. She was anxious to explore the streets and canals of Starda, which she could see from her high windows.

Tentatively, she asked Holtzman for permission to go down to the river, where she had seen many people performing some kind of work. She felt guilty for even asking, rather than working tirelessly on a means to fight the thinking machines. “My mind is a little tired, Savant, and I am curious.”

Instead of looking at her skeptically, the scientist wholeheartedly endorsed the idea, as if pleased to have an excuse to accompany her. “I remind you that we are paid to think, Norma. We can do that anywhere.” He shoved aside a sheet of doodles and sketches. “Perhaps a bit of sightseeing will inspire you to a work of genius. One can never know when inspiration might strike, or where.”

He led her down a steep stairway that clung to a cliff over the Isana. As she stood beside the taller man, Norma inhaled deeply of the river’s smell, sour and peaty from silt and vegetation dragged down from the highlands. For the first time in her life, she felt giddy with her own possibilities; the Savant was genuinely interested in her imagination, her mind, and he listened to her suggestions, unlike the constant scorn she had received from her mother.

Norma raised an idea that had occurred to her that morning. “Savant Holtzman, I have studied your scrambler shields. I believe I understand how they function, and I’ve been wondering if it might be possible to . . . extend them somehow.”

The scientist showed guarded interest, as if afraid she might criticize his invention. “Extend them? They already stretch across planetary atmospheres.”

“I mean a different application entirely. Your scramblers are purely a defensive concept. What if we used the same principles in an offensive weapon?” She watched his expression, detected puzzlement but a willingness to listen.

“A weapon? How do you propose to accomplish that?”

Norma answered in a rush. “What if we could make a . . . projector? Transmit the field into a thinking machine stronghold, disrupt their gelcircuitry brains. Almost like the electromagnetic pulse from an atomic air burst.”

Holtzman’s face lit with comprehension. “Ah, now I see! Its range would be quite limited, and power requirements off the scale. But perhaps . . . it just might work. Enough to knock out the thinking machines within a substantial radius.” He tapped his chin, excited by the idea. “A projector— good, good!”

They walked along the bank until they reached the foul-smelling expanse of mudflats dotted with sloppy pools. Crews of ragged, half-clothed slaves sloshed out onto the mudflats, some barefoot, some wearing boots that extended to their upper thighs. At regular intervals across the featureless field, flat pallets on pontoons held metal barrels. Laborers marched back and forth to the barrels, where they scooped dripping handfuls of the contents and went to plunge their fingers into lines marked in the soft mud.

“What are they doing?” Norma asked. It looked as if they were embroidering the mudflats with their work.

Holtzman squinted as if he had never considered the details. “Ah! They are planting clam seedlings, tiny shellfish that we raise from eggs filtered out of the river water. Every spring, slaves plant hundreds of thousands of them, maybe millions. I’m not certain.” He shrugged. “The waters will rise again, cover the clam plantings, and then recede. Every autumn, harvesting crews dig up the shellfish: clams as big as your hand.” He held up his right palm. “Delicious, especially when fried with butter and mushrooms.”

She frowned to watch the backbreaking labor, the sheer number of people wading in the mud. The concept of captive workers remained strange and unpleasant to her, even Holtzman’s teams of solvers.

The scientist didn’t venture too close to the smell and the slaves, despite Norma’s obvious curiosity. “It’s wise to maintain our distance.”

“Savant, doesn’t it strike you as somewhat . . . hypocritical that we fight to keep humans free from the domination of machines, while at the same time some of our own League Worlds use slaves?”

He seemed perplexed. “But how else would Poritrin get any work done, since we have no sophisticated machines?” When he finally noticed Norma’s troubled look, it took him a moment to realize what bothered her. “Ah, I’ve forgotten that Rossak keeps no slaves! Isn’t that correct?”

She didn’t want to sound critical of her host’s way of life. “We have no need, Savant. Rossak’s population is small, with plenty of volunteers to scavenge in the jungles.”

“I see. Well, Poritrin’s economy is based on having hands and muscles for constant labor. Long ago, our leaders signed an edict banning machinery that involves any form of computerization, perhaps a little more extreme than on some other League Worlds. We had no choice but to turn to human labor, a manual workforce.” Smiling broadly, he gestured toward the mudflat crews. “It’s really not so bad, Norma. We feed and clothe them. Bear in mind, these workers were taken from primitive worlds where they lived squalid lives, dying of diseases and malnourishment. This is paradise for them.”

“They’re all from the Unallied Planets?”

“Leftovers from colonies of religious fanatics that fled the Old Empire. All Buddislamics. They’ve fallen to distressing levels of barbarism, barely civilized, living like animals. At least most of our slaves receive a rudimentary education, especially the ones who work for me.”

Norma shaded her eyes from the reflected sunlight and stared skeptically at the bent-backed forms out on the mudflats. Would the slaves agree with the scientist’s blithe assessment?

Holtzman’s face hardened. “Besides, these cowards owe a debt to humanity, for not fighting the thinking machines as we did. Is it too much to ask their descendants to help feed the survivors and veterans who kept— and still keep— the machines at bay? These people forfeited their right to freedom long ago, when they deserted the rest of the human race.”

He seemed offhanded about it and not quite angry, as if the problem was beneath him. “We have more important work to do, Norma. You and I have a debt to pay as well, and the League of Nobles is counting on us.”

THAT EVENING, GRIPPING the cool metal of a wrought-alloy railing, the small woman gazed out from her balcony window at twinkling city lights. Boats and barges on the Isana looked like waterlogged fire-flies. In the gathering darkness, flaming rafts drifted out from the slave sector, mobile bonfires that floated into the marshes. Each fire rose and peaked, then diminished as the burning rafts sputtered and sank.

Humming to himself, Holtzman came to offer her a cup of seasoned tea, and Norma asked him about the boats. Squinting out at the drifting bonfires, he was slow to realize what the slaves were doing. “Ah, must be cremation rafts. The Isana takes the bodies away from the city, and the ashes are carried out to sea. Basically efficient.”

“But why are there so many of them?” Norma pointed at the dozens of flickering lights. “Do slaves die that often, each day?”

Holtzman frowned. “I heard something about a plague traveling through the worker population. Most unfortunate, requiring a lot of effort to replace them.” He reassured her quickly, his eyes brightening. “Nothing you need worry about, though. Truly. We have plenty of good medicines shipped here, enough to tend all the free citizens in Starda if we should happen to fall ill, too.”

“But what about all the slaves who are dying?”

His reply was not on point. “Lord Bludd has requested replacements for them. There’s a standing order for healthy candidates these days. The Tlulaxa flesh merchants are happy to harvest more men and women from the outlying worlds. Life on Poritrin goes on.” He reached down to pat Norma’s shoulder as if she were a child needing reassurance.

From the balcony, she tried to count the floating fires, but soon gave up the effort. Her tea tasted cold and bitter.

Behind her, Holtzman continued happily, “I very much like your idea of using my scrambler-shield concept as a weapon. I am already thinking of how to design a field-portable projector that could be deployed on the ground.”

“I understand,” she said, her voice hesitant. “I will work harder to suggest new ideas.”

Even after he left, Norma could not tear her eyes from the funeral barges blazing across the river, the floating cremation fires. She had seen how the slaves labored in the mudflats planting clam seedlings and in laboratory rooms calculating hundreds of equations. Now they were dying in droves from a deadly fever . . . but were easily replaced.

The League of Nobles desperately sought to keep from being enslaved by the thinking machines. Norma wondered about the hypocrisy here.