Oblivious to all this—for he had his back to it—Arjun was regarding him coolly, expecting more. Ty went on: “The part on the surface—their answer to Cradle—we don’t know much about. They’ve been building it under the sea.”

“They call it the Gnomon,” Arjun informed him. Then he spelled the word out.

“What does it mean?”

“It used to be the thing that stood up in the middle of a sundial, to cast the shadow. Aligned with the Earth’s axis.”

Ty considered it. “Interesting choice of words.”

“It’s big, Ty. Much bigger than Cradle. There’s a reason they’ve been building it in the ocean. Partly to hide it from us. And partly because it’s too large to construct on terra firma.”

“How big are we talking about exactly?”

“There is only so much I’m at liberty to say,” Arjun said. Then he drew out a tablet and began tapping at it, pulling up a world map, panning and zooming toward the mess of islands between Southeast Asia and Australia. “But just look at this and tell me what you see.” He handed it to Ty.

“Southeast Asia!” exclaimed the Cyc, who had drawn close enough to see all of this over Arjun’s shoulder. “Is there anything you would care to know of it? Or of Sulawesi? Or of Sri Lanka?”

The Ivyn regarded her with fascination.

“I don’t need to look,” Ty said. “I know what’s there. The equator runs through all of that and rarely crosses over the land, and Red never stops whining about it.”

“Not true! Sumatra . . .” said the Cyc.

“A big island to be sure,” Ty said, “but not a continent. Do you remember, Sonar, what I told you about how the Eye works? What Cradle does?”

“Touches the equator,” she returned.

“And only the equator. Which is great if you control Africa and South America. Which Blue does. But most of Red’s territory lies north or south of the line.”

Sonar wasn’t going to be talked down so easily. “Singapore is close,” she said, “and that is connected to Asia.”

“The former location of Singapore is close, yes. But not on the equator. It’s one or two degrees north. Cradle can’t dock there.”

“And that one detail, more than anything else, is what infuriated the Aïdans about the design of the Eye and Cradle,” Arjun put in.

Sensing Einstein behind her, the Cyc leaned comfortably back against him and started rattling off facts—her default mode of social interaction. “Aïdans,” she said. “The ABC hierarchy. Aretaics, Betas, Camites.”

“Camites are a different race,” Einstein reminded her.

“Oh yeah. The relationship of the A and the B to the C is more akin to Symbiosis.”

Ty and Einstein exchanged a wry look.

Oblivious, Sonar Taxlaw gazed down the hill toward Langobard. “Neoanders. And two more. The smart ones and the crazy ones.”

“Jinns and Extats,” Einstein said. “They don’t get out much.”

Arjun’s fascination with seeing a rootstock human had given way to impatience. He focused on Ty again. “This is old history, of course,” he said, “but never forgotten by some people. Way back when the Eye was being designed—I’m talking a thousand years ago—there were alternative schemes proposed. The one we ended up with was simplest, easiest to build with what people had back then. The Eye, the Big Rock, and a small Cradle with sockets on the equator. Great for access to South America and Africa. Almost useless, however, in the stretch of the equator under the habitats where Aïdans, half of the Camites, and most of the Julians lived.”

“What later became Red,” Einstein put in, for Sonar Taxlaw’s benefit.

“One of the reasons Red later coalesced, and built such a strong counteridentity to Blue, was their sense of grievance over this decision. We should have waited, they said. We could have had something much more useful than Cradle.” Arjun zoomed in on Indonesia and dragged out a skinny rectangle, straddling the equator and spanning most of Red’s latitudes. “If instead of Cradle we had made something in the shape of a long arc, spanning a greater distance north-south, it might have connected with Asia down here, where Singapore used to be. And here it could touch the northern cape of New Guinea. And New Guinea could be connected to Australia by dropping enough rocks into the shallows between them.”

“A long arc. Aligned with the Earth’s axis, casting a shadow on the ground,” Ty said, nodding. “A Gnomon.”

“It would have to be huge!” Einstein exclaimed.

Arjun nodded. “Plans for it were drawn up. Studies commissioned on how it might be constructed, in orbit or on the surface. It was deemed too ambitious. So wiser heads prevailed,” said Arjun, “or so it seemed at the time, and we built what we built. We can always make something bigger later, they said. But it didn’t turn out that way. Blue forgot about it. Red didn’t. Their Jinns put as much effort into thinking about it as our Ivyns put into epigenetics. As soon as they closed the border and put up the two turnpikes, they went to work. What have they been doing that whole time?”

“Smiting the Torres Strait with an unceasing storm of bolides,” said Sonar Taxlaw, pointing to the narrows where Australia’s northern cape almost poked New Guinea in the belly. “Filling it in. Damming the currents. Making a wall against those that swim in the sea.”

Arjun nodded.

Then his head snapped around to focus on the Cyc.

He stared at her intently for a moment, then looked at Ty. “Did you . . .” he began.

“Not a word,” Ty said.

“Einstein, did you tell her about Red’s illegal terraforming operation here?” And he tapped the same place on the map.

“First I’ve heard of it,” Einstein said.

“Sonar,” Arjun said, “how did you know about that?”

“The Pingers told us,” Sonar said.

“Who the hell are the Pingers?”

“The people we are going to talk to,” Sonar said.

Beled and Bard had been assisting the Teklan. Those three now approached, carrying the glider packs. They set them down and began camouflaging them under such foliage as was available in this place: scrubby brushes that had been socked into the brow of the slope to stabilize it and provide refuge for small animals. Ty got the feeling, from cues in the Teklan’s physique and general style of movement, that he was some manner of Snake Eater. When it became evident to the Teklan that the two larger men were better than he was at uprooting plants and moving dirt, this man left them to finish the task and approached. Tucked under his left arm was a container matching the general size and shape of those still used, in Chainhattan, to transport pizza. Dangling from that hand was a roughly cubical equipment case. With his free right hand he exchanged salutes with Ty and identified himself as one Roskos Yur. He then set the two parcels in front of Ty and backed away from them.

“Thank you,” Ty said.

“You’re welcome, sir.”

“Why,” Arjun asked, “did you want those? Do you have any idea what it cost to get them here?”

“The Cyc can explain along the way,” Ty said.

Arjun held his gaze on Ty for a moment, then glanced away with a diffident nod. Roskos Yur, by contrast, looked hard at him, and wouldn’t stop looking. After a few moments of this, Ty felt obliged to meet the Teklan’s eye. Now that Ty could scan this man’s insignia more carefully, he could see that he was part of a unit stationed at Nunivak: one of the forward Blue outposts, right up against the border. It was a byword for remote and isolated. It made Qayaq seem like a metropolis. Full of Snake Eaters always being sent off on crazy missions.

“That’s not really what he’s asking, sir,” said Roskos Yur. “He’s really asking, who the fuck are you?”

“Sergeant Major Yur—” Arjun said, in a tone of protest.

But Yur would not be stopped. “And don’t tell us you’re a bartender, sir.”

“The late Dr. Hu handpicked Mr. Lake for inclusion in the Seven,” Arjun pointed out.