This was a human, of course: or rather, a posthuman, gen-enged for this environment, the true, deep heart of Triton, far beneath the cold, attenuated huddles of the surface.

He swum around her smoothly, brushing her legs, feet, arms, chest. She heard a pulsing click, perhaps some form of echo sounding…

He rolled on his back.

Enough analysis, Madeleine.

Without thinking, she reached out with her gloved hand and scratched his corrugated, gunmetal-gray belly. She could feel nothing of the texture of his fur. But the clicks and pops he made deepened, seeming to denote satisfaction.

“Can you hear me? Can you understand?” Are you a Roach too, she thought, some remote, metamorphosed child of Ben and Lena?

For reply he wriggled away and floated there, just out of her reach.

She had to let herself drift a little deeper to touch him again. He let her stroke him a couple more minutes, then wriggled away again. And she had to descend farther, reach out again.

And again, and again.

He’s testing me, she realized slowly. Playing some game with me. Psychology. Still human enough for that.

And, she saw by the swelling of his impressive penis, it was giving him a kick.

She rose up a little, folded her arms.

When he saw she wasn’t playing anymore, he rolled on his front and his fins beat at the water, as if in frustration. But then he quickly forgave her and began rolling around her legs, nuzzling and butting.

More shadows in the water, she saw now: two, three, four Flips. They clustered around her curiously. She wondered if her first companion had called to them, in some manner she couldn’t detect. She tried not to flinch as their powerful bodies brushed the equipment that kept her alive; they showed no malevolence, only a kind of affectionate curiosity, and her gear was surely designed to survive encounters like this.

Now one of them — her first friend maybe, impossible to say — began to emit a new kind of sound. It was a kind of whistle, much purer than the echo clicks or the squeaky-door groans she had heard before.

Another joined in, making a whistle that wavered a bit but soon settled on the same pitch as the first. And now she heard a pulsing, overlaid on their simple pure-tone singing. Beats, she thought, the interference of one tone with another.

The other Flips joined in, singing their own notes, producing more beats. As a piece of music it was simple, just a cluster of pure tones in straightforward harmony with each other. But the beats were more complex, an elusive pattern of pulses that shifted, hopping from one frequency to another, sometimes too rapidly for her to follow.

On a whim she activated a feed to her concrete cave room, up in the surface colony, and let the translator suite record the singing. Then she closed her eyes and let herself drift, immersed in song, oblivious even to the gentle touch of the Flips as they swam around her.

The Flips scattered, suddenly, as if in panic, disappearing into the gloom, leaving her alone. She felt shocked, oddly bereft; without the song, the world seemed empty.

But now she heard a new noise: a deep regular thrumming. Something was approaching through the water ahead of her, something massive, a texture that spanned the ocean.

It was a net.

She paced back and forth in Adamm’s lounge. “What kind of people are you? Those Flips are your—”

“Children?” He smiled, languid, sipping a kind of wine whose principal ingredient was seaweed. “Cousins? Brothers, sisters? Don’t be absurd. They are a different species. They became that way by choice. When they first went into the sea, they took tools, ways of extracting metal. They discarded it all, bit by bit. They even discarded their hands, and their eyes, everything that makes us human. They chose to go back, you see, back to… mindlessness. It was ideological.”

She wondered how much, if any, of that was true. “But to hunt them down—”

He studied her curiously. “Do you imagine we eat them? You don’t think much of us, do you? The Flips are just a pest. They disrupt the ecology. They interfere with the city’s systems, the filter valves for instance…”

Perhaps, she thought.

The translator had analyzed the Flips’ singing.

With no referents, it was impossible to provide a one-to-one translation. But it was obvious the song was full of structure. The suite identified patterns in the choice of frequencies, in the way the beats were manipulated, in their spacing and timing and intonation and pitch… The suite estimated that an hour of such singing could encode a million bits, which was, for comparison, about the information content of Homer’s Odyssey.

The Flips couldn’t match the richness of the whale song of Earth. Not yet. A few more centuries, she thought, and they’d have it.

So the Song went on after all, here in this watery desert, a place even more elemental than the Outback.

Adamm was still talking. “…And you needn’t imagine they are some kind of cute pet. Some of them have turned predatory, you know. Ecological niches tend to be filled… They consume each other. Look, they’re just Flips. They don’t matter.”

“And nor did your ancestors, in white Australia.”

His face hardened. “You created this world, I suppose, with your stunts, firing moons back and forth. And now you want to destroy it, evacuate thousands of people.” He smiled. “History remembers you as a meddler. Grandiose. Ideas above your capabilities.” But even as he spoke he seemed distant, as if unable to believe he was challenging this historical figure — as if he were facing down Columbus, or Julius Caesar. He gazed out at interstellar darkness, the edge of the system. “If these aliens are as powerful as you claim, maybe we should just accept what’s going to happen. Like death. You can’t fight that.”

She growled. “No, but you can put it off.” She stood. “I’m not interested in your opinion of me, or your analysis. I’m going to see the headman, whether she likes it or not. I’ll do what I can to arrange evacuation to the inner system for everybody who wants it. Even the Flips.”

He eyed her, saying nothing; somehow she sensed this remote grandson of long-dead Ben and Lena wasn’t going anywhere, with or without her.

“Good-bye, Adamm.”

Good-bye, good-bye.

Chapter 30

Refuge

The Gaijin flower-ship soared on a fast, efficient, powered trajectory into the crowded heart of the Solar System. The Sun grew brighter, swamping the subtleties of the star-laden sky, its glaring light more and more the dominant presence in the universe.

Madeleine felt an unreasonable, illogical sense of claustrophobia. There were no walls here, and there was room for whole planets to swim through the dark; and yet this place felt oppressive, closed in, like the heart of a city. She spent much time with the lander’s windows opaqued against the yellow-white glare, drifting beneath a cool, austere virtual Neptune.

The Gaijin refused to carry Madeleine any closer to the Sun than the orbit of Earth. She was going to have to proceed on to Mercury in the cramped confines of a lander designed primarily for orbit-to-ground hops.

The few hundred refugees from Triton who had followed her back into the heart of the system would have to endure the same rigors. The transfer into the landers was ill-tempered, chaotic.

It had proved impossible to communicate to the deep-ocean aquatics the need to evacuate. So she had been forced to leave them behind, those dolphinlike posthumans, abandoning them to whatever mysterious fate awaited them, without ever even knowing if they understood what was happening to them.

Just as, perhaps, the retreating Gaijin wondered of her.

As she watched the flower-ship sail away back into the outer darkness, she felt an entirely unexpected pang of loneliness, of abandonment.