“We can’t be inside a dragon. What nonsense,” growled Kohara.
“Maybe ‘inside’ isn’t the right word. We’re within something connected with
Swordfish
’s disappearance. A gigantic egg, maybe, or a nest. Or something else entirely. But I’m certain we’re within
something.”
“Then
Swordfish
should be here too,” said Kameda.
The captain and I exchanged glances. Kameda was probably right; it would make sense. This might well be some kind of habitat or nest. Then again, it might be a huge collective organism. Maybe it spat
Swordfish
out, as it might shortly do to us as part of some
immune reaction. At this point it was impossible to tell.
“Let’s drop Salmon and get the hell out of here,” said Kohara.
“Cap’n, we can’t just—”
“—leave, Kameda? You mean without trying to find
Swordfish
? You’re right, they may be here. But if they are, it means there’s something else here that we need to steer clear of. I don’t see anything we can do to help them. On the contrary—if this creature attacks us, no one can come to our aid.
Swordfish
and
Remora
are the only
vessels in the solar system that can dive these waters.”
“I agree with the captain,” I said. “Let’s release Salmon and clear out of here. Once we have a chance to analyze the data, we’ll have
a better idea of how to proceed.”
Kohara seemed relieved to have gotten backup from a scientist. For my part I was glad to hear him talking sense. The last thing AADD needed right now was more fatalities. The danger to
Remora
was also a danger to AADD. Kameda didn’t bother to argue the point further.
Kohara increased power to the engine. RPM should have risen immediately, but nothing happened. “What’s the story? Why’s she
running so hot?”
“It looks like something’s blocking the cooling intake. I’ll increase
power to the pump.”
At first this seemed to help, but then the intake jammed again. At length, after alternately increasing and decreasing power to the pump, Kameda managed to clear the line and water started to flow again. The engine began to settle down, though it was still
running a bit hot.
But a still bigger problem awaited us. When Kohara engaged the screw, nothing happened. We were dead in the water.
“Cap’n, the protection circuit just kicked in.”
“I was half expecting that.”
“What’s happening?” I said.
“Something’s tangled in the screw. If the load exceeds a certain level, a protection circuit cuts power to the motor. For some reason
that just happened.”
“Is it the same thing that blocked the cooling intake?” The radar showed nothing ahead of
Remora
—not even fish, much less a dragon.
“Dr. Kurokawa, we still have Salmon, right?”
“Yes, I haven’t released the cable yet.”
“Can you walk her around the ship and see what’s out there?”
I routed Salmon’s sensing data to their webs, so they could monitor its progress, and began to guide the robot toward the rear
of the boat.
“What the hell is
that
?” Everyone froze. More than half the length of
Remora,
from the screw forward, had disappeared down the gullet of some giant creature. “Now we know why the screw
won’t turn.”
It seemed to be the same as the creature captured by
Swordfish
’s radar, but not quite as large. The tail was quite a bit shorter and the body was more compressed. It reminded me of a hydra—not the nine-headed monster of Greek myth, but class Hydrozoa, family Hydridae, genus
Hydra.
On Earth these tiny water-dwellers had rubbery, tubular bodies they could compress or extend to swallow food larger than themselves. The thing that was busily trying to swallow
Remora
looked almost identical. Or maybe it was some
jellyfish-like species?
Kohara grabbed the hydrophone to alert the support team, but the creature’s body attenuated the ultrasound. Communication was now impossible. Up on the surface, they were probably already
panicking.
“Why didn’t we just send a robot in the first place and have done with it?” muttered Kohara. “Then we wouldn’t be dropping like flies.” This was directed at me. I wasn’t in a position to disagree, but for AADD the right course consisted of demonstrating to the people of Earth that we would go to any length to investigate the
possibility of extraterrestrial life. And now here we were.
“Come on, Captain,” said Kameda. “This mission is too important to leave to robots. Hey, it’s really hot. It’s forty degrees!”
“Where’s the air conditioning?”
“Hold on… Protection circuit again.”
“What the hell for?”
“We can’t vent the heat. The system won’t run above a certain
temperature.”
Just then we were all struck by more or less the same thought. The water temperature was five degrees. Why would heat be building
up in the boat?
I hurriedly switched Salmon’s sensors to infrared. The surface of the creature’s body was almost as cold as the surrounding environment. But by now the cooling water from
Remora
must be quite hot—which would make this coldness impossible unless the cells of the creature’s body were highly insulating. This wouldn’t be surprising if its only source of energy was heat from hydrothermal vents.
“Maybe we should take a sample with the manipulator,” said Kameda.
“We don’t have time to analyze it.”
“It’s not the sample, Captain. It’s what happens when we take it. Maybe it’ll spit us out.”
“You’re going to have a long life, Kameda.”
“That was the general idea.”
I wasn’t sure the creature would respond to pain by spitting us out—or if it would even experience pain at all. But we decided to try. It might give us a clue as to how to escape. And if we were destined to die, we wanted to know something about what was to kill us.
Luckily
Remora
’s manipulator was mounted on the bow. It was a huge gripper, like the oversized claw of a fiddler crab, with separate, smaller arms extending to either side for precision work. Each appendage was equipped with a camera. The surface of the gripper was translucent and could emit light for illumination, eliminating the need to manipulate spotlights. The visibility outside was poor,
but not so poor as to completely obscure the tip of the gripper.
I grasped the manipulator’s joystick for the first time. Facility with the controls wasn’t as important right now as familiarity with the thing that was about to be manipulated. And if I didn’t handle this myself, I wouldn’t be doing my part to help deal with the danger.
Remora
’s pressure hull was ultrapure specialty steel, the number of openings in it kept to a minimum. The manipulator and its cameras were controlled by a computer in a separate pressure hull; a single strand of optical fiber led to where I sat. Most of the manipulator’s movements were AI-controlled, leaving only selection of objective and sequence of operations to the operator. I had a pseudosensation
of touch through the glove, but no sense of force feedback.
I moved the gripper cautiously. The creature ignored it. The cameras showed more than half the ship engulfed in a gray-white mass. As if from a great distance, I heard someone’s voice say nervously,
“I’m taking a sample.”
It occurred to me that the thing attempting to swallow
Remora
might be a different species from the one that had attacked
Swordfish.
I had a feeling the creature would not react. The gripper brushed against the creature. No reaction. I pinched a fold of tissue with the gripper. The surface rippled like jelly, but there was still no reaction.
“Dr. Kurokawa—look at the temperature.”
The manipulator was tipped with a simple sensor array. The temperature under the creature’s skin was close to forty degrees. I gingerly lifted a large section of tissue with the gripper. To my surprise it immediately tore away, the detached tissue quickly reforming itself into a sphere. No fluid leaked from the wound,
which closed up in seconds.
“Is this thing indestructible?” marveled Kohara.
“Captain, it may be an alien life-form but I doubt it’s indestructible.” A theory was forming in my mind based on what we were seeing. The sphere of tissue drifted toward the manipulator like a ball in a zero-G game of water polo. I guided it into a collection cylinder on the hull with one of the smaller manipulator arms.
Remora
had six of these containers, each with a chamber—almost a miniature laboratory—equipped with a microscope, chemical sensors, manipulators, and other simple experimental apparatus. It was vital to ensure that no samples actually entered the ship, where the risk of contamination in either direction would be hard
to control.
I sealed the collection cylinder, evacuated the water, and moved the sample into the testing chamber. I took a slice of tissue with the
manipulator and examined it carefully with the microscope.
“Take a look, Captain. Here’s your dragon.” The monitor showed a confused jumble of cells of all sizes and shapes, some similar, some very distinctively different. Some cells were fibrous and long, others were organized into lumps of a single cell type. Everything was enveloped in some gelatinous, transparent substance, probably
macromolecular.
“I don’t see any real structure,” said Kohara.
“It looks like chaos, but I think it’s probably an organized chaos. These are cell colonies. We may be looking at an ecosystem.”
“An ecosystem?”
“I won’t be able to confirm it until we return to the base and I can run these tests on better equipment, but this gel-like substance is probably an insulator. This is probably how colonies store heat from hydrothermal vents. Those vents are going to be localized, their heat a precious resource. The whole ecosystem of cell colonies would be organized around this trapped heat. The interior contains warm water. The water outside the ecosystem is close to freezing. The thermal gradient could drive cellular metabolic
activity.”
“So that’s why the piece you pulled off formed into a sphere, to
retain the heat?”
“It’s the most efficient shape for minimizing surface area relative to volume. The surface would include cells that are hypersensitive to changes in the temperature. This far from the ocean floor, waste heat from our cooling system would be a very attractive source of energy. And these cells here”—I zoomed in with the monitor—“are
probably the source of this insulating substance.”
The spherical cells on the monitor were by far the most numerous. Around three-quarters of their volume was a reservoir for that
strange, transparent slime.
“So is this what got
Swordfish
?”
“The heat from
Remora
’s diesel is really pretty minimal. But
Swordfish
used proton/antiproton annihilation as a power source. That would create a huge heat wake. I don’t think anything was actually chasing them—I think the ‘dragon’ they saw was cell colonies
forming in their wake. The truth is as simple as that.”
Kohara nodded. “And the faster they went, the more heat they
put out and the faster the colonies formed behind them.”
“Ultimately the entire ship would have been enveloped, blocking the cooling vents and bringing the ship to a halt. But without knowing what was happening, the crew would have continued applying power to try to escape. And that could have taken them
below crush depth.”
“But, Dr. Kurokawa, if you’re right, there’d have to be billions of loose cells in every cubic centimeter of Europa’s ocean. We haven’t seen any evidence of that.”
“
Swordfish
and
Remora
both encountered waters with much higher ambient cell concentrations—and in both cases, the concentrations skyrocketed without warning. My guess is that the wall we passed through is the outer surface of the real ecosystem.”
“What do you mean by ‘real’?”
“The usual form this ecosystem takes on Europa—a gigantic balloon coated with insulating gel. The balloon’s volume increases by the cube of its radius, while the surface only increases by its square. So the bigger the better—a giant sphere is the most efficient way to exploit large amounts of trapped hydrothermal energy. Europa may harbor millions of these spherical ecosystems, hundreds or thousands of meters across. The trapped heat causes the colonies to rise. After they cool, they descend again to the seabed, to recharge around another vent or dissociate until the next thermal opportunity presents itself. That’s why we only found traces of life—until we penetrated the wall.”
“Look, Dr. Kurokawa. I’m not arguing for the sake of arguing, but if these ecosystems form as you say, what would they be doing at these shallow depths? If the heat the cell colonies need is on the seafloor, wouldn’t venturing a hundred klicks away be suicidal? There’s no heat source this far up, unless you’re lucky enough to run into the occasional submarine.”