Rhea was different. For one thing, Chris was closer to the central Rhea vertical cable than he had ever been to Hyperion's great column. A black shadow that leaped from the sea, it dwindled rapidly and kept rising and rising until it vanished completely. To each side of it were the north and south verticals, improperly named because they both angled toward the center, though not nearly so much as the ones behind him, to the west. The cables vanished because of the darkness, but more important, because Rhea did not have a window arching over it. Rhea lived in the shadow of the vast trumpet-shaped mouth known as the Rhea Spoke.
Had he not known its size and shape from pictures, Chris would never have discovered its true geometry. What he could see was a dark, wide oval high overhead. In reality, it was more than 300 kilometers above the sea. Around the edge of that mouth was a valve that could close like the iris of an eye, isolating the space above it from the rim. It was now wide open, and he could see up into a dark, oblate cylinder the upper end of which, he knew, was another 300 kilometers away, where another valve led to the hub. He could not see that far, through that much dark air. But what he could see resembled the barrel of a gun that might have used planetoids for projectiles. It was aimed right at him, but the threat was so overblown he could not take it seriously.
He knew that between the lower valve and the radius of the Hyperion Window-a vertical distance of about a hundred kilometers-the spoke flared like the bell of a horn until it became one with the relatively thin arch of roof that stretched over the daylight areas on each side of Rhea. Try as he might, he could not see that flaring, though it had been discernible from Hyperion. Another trick of perspective, he concluded.
There were lights somewhere up there in the spoke. He supposed they were the windows he had read about. From here they dwindled like runway lights seen from a landing plane.
He gradually became aware of a more immediate light, to his left and over his head as he reclined on the deck. He sat up and turned around and saw that the surface of Nox was being lit from below with a pearly blue luminescence. At first he thought it was a hive of the sea insects Cirocco had told him about.
"It's a sub," said a voice to his right. He was startled; Cirocco had joined him silently. "I sent messengers a few hours ago, hoping to attract one. But it looks like she'll be too busy to give us a tow." She pointed at the sky to the west, and Chris found a big patch of deeper darkness against the night. He didn't need anyone to tell him it was a blimp, and a big one.
"Not many people have seen this," Cirocco said quietly. "There aren't any subs in Hyperion because there're no seas. Blimps go anywhere, but subs stay where they're born. Ophion won't hold them."
There was a piercing series of whistles from the blimp, followed by a sizzling and hissing from the rear of Constance. Chris understood that the blimp had asked for the fire to be put out, and the Titanides had complied.
He felt Cirocco's hand on his shoulder. She pointed over the water. "Right there," she said. He looked, still conscious of her hand, and saw tentacles writhing upward, thrashing slowly against the water. A slender stalk rose from the mass of them.
"That's her periscope eye. This is about as much of a sub as you'll ever see. Notice the long swelling there on the water? That's her body. She never comes out any more than that."
"But what's she doing?"
"Mating. Be quiet, don't disturb them. I'll fill you in."
The story was straightforward, though not obvious. The blimps and subs were male and female of the same species. Both descended from the sexless children of their union, which were snakelike and nearly brainless until competition had reduced their swarms to a small number of twenty-meter survivors. At that point they grew a brain and tapped some racial source of knowledge that neither Gaea nor the blimp-subs had ever explained to Cirocco. It had nothing to do with nurturing, for from the time they were spawned neither the mothers nor the fathers had anything further to do with them.
But they grew wise in some mysterious way, and eventually made a conscious decision to become male or female, blimp or sub. Each entailed a hazard. The water contained many predators which ate young subs. There was no such risk in the air, but a young blimp could not manufacture his own hydrogen. His fate after metamorphosis would be to sit on the water, an empty bladder, and hope a mature blimp would, so to speak, blow him up. No adult could support more than six or seven in his squadron. If there were no openings, it was just too bad. The decision to differentiate was irrevocable.
The blimps and subs had little to do with each other. They might never come together at all at the watery interface between their worlds but for two facts. There was a species of seaweed that grew only in deep water; without it, the blimps could not survive, and the Titan trees-massive spurs of the body of Gaea herself, growing more than six kilometers tall and only in the highlands-sprouted leaves near their tops which were vital to the diets of subs.
Amicable mating was in the interest of both sexes.
Something fell from the tendrils which dangled below the midships bulge on the great curve of the blimp's belly. It splashed into the water. The sub's tentacles gathered it in and made it vanish. There was a deep sigh as the blimp vented hydrogen and sank toward the outstretched arms of his lover.
Beyond that there was not much to see. The tendrils entwined and the massive bodies touched at the surface of the sea, and they just stayed that way. It was only when waves began to roll the raft that Chris realized how much activity might be concealed by distance.
"There is a lot happening," Cirocco confirmed. "There is a way to get closer to the action, by the way. I was once a passenger in a blimp when he got smitten by love. Let me tell you ... never mind. It's a rough ride."
Cirocco went away as quietly as she had come. Chris continued to watch. Before long he heard hooves on the deck, and Valiha came around the cabin to join him. He was sitting on the edge of the raft, his feet dangling over the side to just reach the water. Valiha sat the same way, and for a moment a trick of the shadows made the equine part of her body vanish. She became a very big woman with shrunken, spindly legs, dangling her devil's feet in the water. The image upset him, and he looked away from her.
"Beautiful, isn't it?" she asked, in English so singsong that for a moment he thought she had sung it in Titanide.
"It's interesting." In truth, he was beginning to tire of it. He was just about to get up when she took his hand, raised it to her mouth, and kissed it
"Oh."
"Hmmm?" She looked at him, but he could not think of anything to say. It apparently didn't matter. She kissed him on the cheek, the neck, and the lips. He took a deep breath when he was able.
"Wait. Valiha, wait." She did, looking at him with her great, guileless eyes. "I don't think I'm ready for this. I mean... I don't know what to tell you. I just don't think I can handle it. Not now." She continued to search his eyes. He wondered if she was looking for madness, decided that was his own fear speaking. At last she briefly pressed his hand between both of hers, nodded, and let him go. She stood up.
"Let me know when you are. Okay?" She hurried away.
He felt bad about it. Though he tried to analyze his reasons for rejecting her, nothing satisfied. Partly Valiha was a reminder of something he had done while possessed. He was a lot braver at those times, unless he was a lot more timid. It looked as if that had been a brave time because try as he might, he could not come up with a comfortable answer to one question: what did a Titanide and a human do? And another: how much life insurance would he need before attempting it?