“Neither,” Kebes said. “They’re numbered in numbers.”

Sokrates looked blank.

“You know, zeroic. Like page numbers in books,” I said. I pulled a book out of the fold of my kiton and showed him. It happened to a bound copy of Aeschylus’s Telemachus.

“Those are numbers?” he asked. “How do they work?”

I wrote them down in the dust, from one to ten, and showed him. “That’s all there is to it. For twenty, or for a hundred—”

He understood it at once. “And you have all known this all this time and never mentioned it to me?” he said.

“It never occurred to me that you didn’t know,” I said.

“Pah. My ignorance is vast and profound. I like to know at least what I do not know.” He traced the numbers again. “Zero. What a concept. What a timesaver. What vast realms of arithmetic and geometry it must reveal. I wish Pythagoras could have known it, and the Pythagoreans of Athens.” Then, like a hound who had started after the wrong hare, he got immediately back on track. “So the workers are labelled with this?”

“That’s right,” Kebes said. “All of them.”

“Who did this?”

“I don’t know.”

“What is the purpose?”

“Telling them apart. That’s how Lysias uses it, anyway.”

“Did you note the number of the one planting bulbs?”

“Sorry, no, it didn’t occur to me.”

Sokrates sighed, sat back and absently ate a handful of olives.

“So the numbers are like names?” I suggested. “That seems to argue against them being people. Why not give them names?”

“Maybe there are too many to name?” Pytheas suggested.

“How many of them are there?” Sokrates asked, licking olive oil off his fingers.

We all shrugged. “Lots,” Kebes said. “I was surprised how many when I saw them at their feeding station.”

“They eat?” Sokrates asked.

“They eat electricity, Lysias said.”

Sokrates bounced to his feet. “Come on, show me this feeding station!”

I swallowed an olive hastily. We set off, with Kebes leading the way and Sokrates close behind.

Pytheas walked beside me. “This is crazy,” he said.

“Sure. Kind of fun, though. And what if they actually were thinking beings with plans?”

“They’re not. They’re tools. Everyone knows that.” Pytheas looked a little unsettled.

“What everyone knows, Sokrates examines,” I said.

Kebes led us to a block on the east side of the city, between the streets of Poseidon and Hermes, not far from the temple of Ares. The whole block was one square building, relatively unexciting. I’d never particularly noticed it. There was a lot in the city that was empty, awaiting a later purpose, or used by the masters for unknown purposes. I wasn’t especially curious about most of it. This building had decorative recessed squares set all around it at ground level. There were no windows. A key-pattern frieze ran around the top. There was another key pattern over the door.

“What now?” Sokrates asked.

“Now we wait for a worker, because Lysias has a key but I don’t. But you’ll see when a worker comes.” Kebes leaned back on his heels. I squatted down and ate more raisins. Pytheas and Sokrates began to debate volition, and whether workers could be considered to have it.

“Ah, here we go,” Kebes said, when the sun was beginning to slide towards dinner time.

A bronze-colored worker came down the street. “Joy to you,” Sokrates said. “I am Sokrates. Do you have a name?” It ignored him utterly and approached the building, not by the door but directly at one of the recessed squares. The square slid open in front of it and it vanished inside.

“Did you see that?” Sokrates asked.

“That’s what they do,” Kebes said. “Inside there are sockets and they plug themselves in to eat electricity. When they’re full, which takes several hours, they unplug themselves and come out again.”

“I’d never noticed this was here,” I said.

“Nobody much comes down this street,” Kebes said. “There’s nothing here, and if you were at the corner you’d cut diagonally down the street of Apollo.”

“You’ve been inside?” Sokrates asked.

“Yes, with Lysias.”

“We could follow a worker inside,” Sokrates suggested.

“We’d be stuck there until one wanted to come out. We can’t open the doors without a key. It would be better to talk to them when they come out—they won’t be hungry then, and if they can talk they’ll be more likely to respond.”

“I want to see inside,” Sokrates said.

“All right. But we could get stuck there all night. Or you could ask Lysias or Klio. They have keys. I’m sure they’d let you in.”

“If Lysias and Klio take care of them, that suggests that they come from their time. When is that?” Sokrates was bending down and poking at the square where the worker had disappeared. Nothing he did could move it. I touched it myself. It felt like solid stone.

“The boring part of history,” I said. “The bit where nothing happened except people inventing things, Axiothea said.”

“The part they don’t want us to know about! Excellent.” Sokrates kept on poking. Then a different square slid open and a worker emerged. “Joy to you! Do you like your work?” It ignored us. The panel started to slide shut, and fast as an eel, Sokrates darted through it.

The three of us stared at each other and then at the smooth closed panel. “He needs a keeper sometimes,” Pytheas said.

“Should we get Lysias?” Kebes asked.

“How much trouble can he get into inside?” I asked.

“Not much, I don’t think. He knows about electricity—I mean, he has a light in Thessaly. He’s not likely to stick his fingers into sockets. At least, I hope not. He can’t get into much trouble going up to the workers as they’re feeding and asking them if they like their work.” Kebes looked worried.

“I think we have two choices: wait for a worker to go in or out and follow it in ourselves, or fetch Lysias or Klio and ask them to let us in,” I said. “We can’t just leave Sokrates in there.”

“I think you should go and find one of them,” Pytheas said, to me. He tapped on the stone. Nothing happened.

“It might be hours before another one comes,” Kebes said.

“It’s almost dinner time. Klio will be at Sparta, and Lysias will be at Constantinople. I’ll go to him, you go to her,” Pytheas said, looking at me. Then he looked at Kebes. “You’ve been in there before. You wait here, and if you get the chance, go in.”

Kebes hesitated, as if he wanted to dispute this, but it made such clear and obvious sense that after a moment he nodded.

“Back soon!” I said, and set off running towards the Spartan hall.

“Sokrates is doing what with the workers?” Klio asked, when I found her and panted out my story.

“Trying to initiate dialectic with them,” I said. “But Kebes said he might stick his fingers in a wall socket, and I’m not absolutely sure he wouldn’t.”

Klio sighed. The Spartan hall was appropriately bare and Spartan, but all the wood was polished to a high shine and the windows looked out over the sea. The smell coming from the kitchen suggested a rich vegetable soup. My stomach gurgled. “Come on then,” she said. “I suppose we should sort this out. What made him imagine he could have a dialogue with them?”

“He’s Sokrates,” I said.

“He’s like a two-year-old sticking pencils in his ear,” she said.

“Well, but there were also the plants.”

“Plants? No. Tell me on the way.” She pushed her hair out of her face and we set off.

I explained to Klio about the bulbs as we walked. She frowned. “They really are just tools,” she said. “I can see how it’s difficult for you to see. They can make simple decisions, they can even prioritize to a certain extent. But they don’t really think. They have a program—a list of things they know how to do and a list of orders of what needs doing, and they just put those together.”

“Do you know that or is it an opinion?” I asked.