Грег Иган - The Year's Best Science Fiction, Volume 1

In the meantime, the toroids continued their labors, and after fifty hours, their efforts were rewarded. Under ordinary conditions, each of the five hexapods could work at full capacity under her own power for approximately three days before returning to a charging station. Every such trip represented a loss of valuable time, and after taking into consideration the conditions under which they would be operating, their designers had arrived at an elegant alternative.

The solution was based on the nature of the vent itself, where the dissolved sulfides issuing from the crust provided a source of energy that could thrive in the dark, as bacteria converted hydrogen sulfide into the sugars and amino acids that formed the basis of a complex food web. It was the only way that life could exist under such harsh conditions, and it was also what would allow the hexapods to carry out their duties over the weeks and months to come.

When Eunice felt her power fading, she went to Wagner. The toroids were no more than a few meters from where she had left them, although she knew that they had been systematically farming the sediment the entire time. As they inched along, they sucked up free sulfides, which served as a substrate for the microbial fuel cells—filled with genetically modified versions of the same chemosynthetic bacteria found here in abundance—that were stacked in rings inside their bodies.

Eunice positioned herself above the toroids and signaled to Wagner, who slipped up and around her middle. As the rest of the hexapods did the same, she felt a surge of energy. It was a practical method of recharging in the field, but she soon found that it also left her with a greater sense of kinship to the life that she was studying, which relied on the same principles to survive.

The cycle of renewal gave shape to their days, which otherwise were spent in work. Once a week, a hexapod would go up to transmit the data that they had collected. There was no other practical way to communicate, and these visits amounted to their only link with home.

On the third week, it was Eunice’s turn. After ascending alone for nearly an hour, following an acoustic signal, she surfaced. The yacht was holding station exactly where it was supposed to be, and as she swam toward it, she heard a familiar voice in her head. “How are you doing?”

A scoop net lifted her onto the deck. As Eunice rose in a gentle curve, feeling slightly disoriented from the unaccustomed movement, she tried to seem nonchalant. Her lights flashed. “Happy to be here.”

The net was handled by a deckhand whose clothes she didn’t recognize. He deposited her into a tank on the boat, and once she had righted herself, she saw James seated nearby. She could tell without counting that there were fewer people in sight than there had been on her arrival—the human crew spent the week onshore, returning to the rendezvous point only to pick up the latest set of observations. Aside from James, none of them ever spoke to her.

As Eunice wirelessly shared the data, she kept one line of thought fixed on her friend. “Are you pleased with our work?”

After receiving the question on his console, James entered a reply. “Very pleased.”

Eunice was happy to hear this. Her thoughts had rarely been far from home—she wouldn’t see the charging station or the seven sisters she had left behind until after the survey was complete—but she also wanted to do well. James had entrusted her with a crucial role, and it had only been toward the end of her training that she had grasped its true importance.

A month earlier, after a test run in the harbor, Eunice had asked James why they were studying the vent at all. His response, which she had pieced together over the course of several exchanges, had done little to clarify the situation. “There are metals in the sulfide deposit. They precipitate there over time. Some people think that they’re worth money. Even if they aren’t, we’ll have to go after them eventually. We’ve used up almost everything on land. Now we have to turn to the water.”

Eunice had tried to process this, although fully half of it was meaningless. “And me?”

James had typed back. “If we want to minimize our impact on the life at the vent, we need to know what we’re trying to save. You’re going to tell us what lives there. Not everyone cares about this, but there are regulations that they need to follow. And I’ll take the funding where I can get it.”

Eunice had understood this last part fairly well. Funding, she knew, was another form of energy, and without it, you would die. But this had left another question unanswered. “So what do you really want me to do?”

James had responded without hesitation. “You’re going where I can’t. These vents are special. They may even have been where life began—they’re chemically rich, thermally active, and protected from events on the surface. The ocean is a buffer. A refuge. This is our best chance to study what might be there. And—”

He had paused. “And it could end at any moment. There are people here who want to start mining right away. If they can convince the others to take their side, they might do it. Your work may keep us from destroying what we don’t understand. That’s what I want from you.”

Other questions had naturally arisen in her mind, but James had seemed distracted, so she had held off. Seeing him again now at the survey site reminded her of the exchange, and she resumed her work with a renewed sense of purpose. She had always been aware of the beauty of the vent, but now she grew more conscious of its fragility. Perhaps, she thought, she might even play a role in saving it.

And then everything changed. One day, Dione came down from a scheduled data delivery, long before they had expected her to return, to share some disturbing news. “There was no yacht.”

The others all stopped what they were doing. Thetis’s lights flashed. “You’re sure?”

“I followed protocol,” Dione said. “There were no signals on the way up and nothing on the radio.”

After an intensive discussion, which lasted for nearly ten seconds, they decided that there was no cause for concern, since they had been trained against the possibility that the yacht might occasionally be delayed. Their orders were to continue working as if nothing had changed, and if they received no signals in the meantime, to check in again at the appointed hour.

A week later, Clio went up to find that there was still no one there. Seven days later, the lot fell to Eunice. On reaching the surface, she saw nothing but the empty ocean, and when she switched on her radio, she found that all frequencies were silent. Her range was very short, but it confirmed that there was nothing transmitting within several kilometers of their position.

Eunice sank down again. On her return trip, she found herself brooding over what James had said. He had seemed concerned that they wouldn’t be able to continue the project for long, and although it seemed unthinkable that the five of them would simply be abandoned here, the idea weighed enough on her mind that she felt obliged to speak to one of her sisters.

She chose Galatea, with whom she was the closest, but when they withdrew to a distant part of the vent field, her sister seemed unconvinced. “I don’t know what else we can do. We can’t leave. You’ve seen the map.”

Eunice knew what she meant. They depended on a steady supply of hydrogen sulfide. Without it, they would lose power within three days, and if they left this energy source, there was no guarantee that they would find another. The known vents were an average of a hundred kilometers apart, and they could travel no more than thirty without recharging. “We have to do something.”

“But we are. We’re following our instructions. That’s enough for now.” Galatea had turned and swum away. Eunice had remained where she was for another minute, trying to convince herself that her sister was right, and she had finally returned to work. She had continued her observations, ignoring her growing uneasiness, and she might have stayed there forever until—