The clockwork object began its descent process soon after it landed. First came the booms as it blew the wheels off. Then the long fan-shaped-chain and the wheels.

The decapods scattered at the sound. They sensed the object’s change from the noise.“It is like a tubular building.” Study-up said.

The decapods listened as it ran through its pre-programmed dive into the ice. They fled and came back.“What is it doing?“

Within a few dozen moments, they sensed a change. Ice-Driller ventured a and the image returned to them. They could now see it was coming their way. Carving through the ice. They were still directly underneath it, with only a thin layer between them.

“Swim! Before it blows the top.” Thermal-Rock said.

“Some sort of chemistry is generating all that heat.” Study-Up concluded before being grabbed by the three others.

The object deliberately stopped after descending one length of itself. The reasoning was unknown to the quartet of decapods who moved themselves out from under the hot and heavy craft. They bled back to the safety of the building.

After a bit of time, parts separated in the slush meltwater, and it left a small cylinder pushed up through the ice.

The decapods sent another from a distant safe location at the object.

“It stopped, and is now different.” Study-Up said. She swam back to the object.

They heard a massive come from the object. The loud visualization sound in a frequency the decapods did not use. Their minds had already grappled with the facts, but now had to wrangle more unknowns down to the bedrock of their minds.

“It visualizes like we do!” Study-Up said. It was as though she was frozen in ice, such was her unwillingness to leave the area.

“Hurry!” Ice-Driller grabbed her and pulled. She snapped out of her awe and swarm on her own accord. They fled again to the insulated building and entered. The room was still warm, which the decapods appreciated. They listened to the object via the top hole, but little sound came. Everyone was quiet, and the world was silent. Even the occasionally creaks of ice were muffled by the walls.

Though once again ensconced, boredom was far from their minds. First, they brought The Overworld Stone into their quarters. And second talk of The Object, and carefully listening outside, dominated all time.

They did a few close-in readings of the Overworld Stone, but discovered little else from looking at the object. It was metal, but they tested the displacement anyway to get an estimate of its density. They tried to rest until something new happened.

“What if the Object does nothing more?”

“Then we’ll split up. You and I will leave, and the other two will stay behind and observe.” Ice-Driller said.

The space probe, or The Object as the decapods tentatively called it, stayed in the ice for an hour, pointing downward. During this time, it slowly melted the bottom ice and gave the ice behind it time to refreeze. This was imperceptible to the decapods, but mission planners wanted to reseal the ice. The official name of the submarine probe was the Europan Life Finder (ELF), though the scientists often only referred to the instruments they specialized in.

ELF melted down through the ice by warming the mineral oil inside by passing it over the radio-isotope-generator (RTG) and passively moving it towards the front while recirculating colder oil to the rear. As it descended the back module, the Sub-Ice Disk reeled out rugged communications and power line to the Comms Module, or CM. The CM was which partially embedded in the ice, its electronics were shielded by a meter of ice and a long antenna could be stowed in a protected state. Coiled behind the object were comms and power lines which gave a helical shape so that when the ice refroze it produced a spring-like shape through the ice. The designers thought this to give the entire system extra longevity in the shifting ice.

Downward, the object dove into the forever dark. Light barely penetrated through the ice and by the end of the ice it was complete darkness and had been since the formation of Europa.

At regular intervals, the probe sent out a sonar ping. During the descent, it also tested the instruments, the cameras, the impellers and other systems. Meanwhile, it sent the communications up to the Comms Module, then relayed back to earth where it was picked up by the Deep Space Network’s series of dishes in California, Spain, Chile, and Australia.

One of the first scientific instruments used was the flow cytometer. This device took in samples of the near-freezing water, shot pulses of laser light, then used the scattered or fluorescent light to detect life. The initial data was already promising and fulfilled a heavily voted task of ‘Discover Single-Cell life’. From the artificial intelligence’s perspective, it was scoring points and had descended only a few meters. Should it fulfill all voted science goals, it would be assigned an automated seafloor mapping with whatever remaining mission life the sub could muster.

Ice-Driller heard another ping and woke up from a light snooze. “There it goes again! The Object sounds closer.” He had left the top listening hole open during his nap so any changes in the status quo could be examined.

The other decapods stirred.

Ice-Driller exited the building, squeezing his body through the porthole.

He sent out a loud sound to get a sense of the surrounding ice. The surrounding area looked like he’d remembered, but around the corner a weird reflection of echoes gave him clues to where the machine was.

He swam up to a small hole and peered inside with his sound melon. Then he heard the whirl of something high frequency. Something he’d never heard before.

The machine was like an ascender, a moveable building that seemed to have impressive control of its ballast to move around the small, interstitial lake. It had already shed another part, like a crab needing a new shell.

Ice-Driller faced the machine. He could hear it directly in front of him. Panic set in and he flashed red and then swam away.

the object sent a sonar pulse toward the water that Ice-Driller had just left. The sonic energy would have been deafening but for one adaptation. Decapods have the automatic ability to ignore other loud pulses of sound from themselves or a nearby source. This allows them to ignore the pulse, but listen to the echoes, which are many times fainter than the original sound. The submarine’s ping was not so alien of a frequency that the acoustic self-deafener didn’t respond.

Ice-Driller heard the auto-muffled ping and caught the echoes from the surrounding area. He swam back and told the others what he had heard. When they got over their excitement, they swam out towards the machine. It had now melted through and was navigating the chaotic terrain.

The decapod skin has photoreceptors that were sensitive to infrared and enabled the creatures to see the temperature of nearby objects.

“I can see it! It has a constant identity.” Sand-Stirrer said.

Thermal-Rock clicked off an sound absentmindedly. Each of the decapods flushed their skin with a heat and flashed back with their unique visual identity to everyone around. The submarine kept a constant heat on the front of the craft as it melted through the ice through the small hole.

“Amazing!” they gasped.

For the next hour or two—which was roughly near a deci-sleep, or a tenth of a decapod day—the four each tried to talk to the submarine with various sounds. They tried normal Decapod basic words, then math with a countable series of clicks in base ten and base eight, then the echoes of common objects as best they could reproduce (shapes, fish, and sharks, for example). No communication seemed successful as the submarine continued to worm its way through the small broken ice passages downward out of the ice shelf.

“We are from Deepvent.” Ice-Driller said to the mute machine.

“Use sono-pictures instead. It doesn't know from , but it would know a ◯ from a △ .” Study-Up said.

At this Ice-Driller said ‘Deepvent’ and instead of using the colloquial name, instead used an image of the city: A mound on the seafloor with up-flowing current.

The submarine understood it was in the iceshell of Europa, melting through chaotic terrain: holes, shafts, cracks mixed with pressurized lakes and plumes. The AI detected an unsent echo. It stopped and sent out a . Seeing as it was certainly not near the seafloor, the AI chalked it up to 'strange' data, ignored it presently, but filed the information away in its database. Then it continued the slow process of unreeling the SubIce Module from the Communications Module. It now descended the large water shaft. Unknown to the machine, or those on earth, the shaft penetrated down to the bottom of the ice. Nothing else would stall its progress. It descended, all the while recording its surroundings, summarizing it, and held the summary in data until it could transmit it back.

Thermal-Rock listened to the mental image Ice-Driller had projected it. He changed it more to make it look like an undeveloped hot thermal vent. Then he got in front of the submarine and sent out a mental image. At this the submarine moved slowly towards Thermal-Rock and sent out another ping directly at Thermal-Rock, who had been the source of the sound, then it continued its descent.

“I think it is interested.” Ice-Driller said and complemented Thermal-rock with a slap of the tentacle.

“Do you want to see the hot vents?” Thermal-Rock asked the machine. He then made his best impression of the sound of the hydrothermal vents, at least the natural ones he could remember.

No vents were left in their natural state on the seafloor. The flow rights were 'hotly' contested by decapod society. All wealth and life flowed from them. The poor on the outskirts, the rich in the center. To be sentenced to exile meant poverty and starvation. Thermal-Rock had once visited a museum that kept a hot vent in its ‘natural state’. Every few tides, a vent could flow unhindered until eventually sediment needed to be swept away. Studious decapods came to see this at least once in their academic careers.

At this projected sound, the submarine turned on its lights and examined the area. Most of this portion of the electromagnetic spectrum passed around unnoticed by the decapods, but they detected a change in infrared, but that was still over flushed by the heat the submarine bow made. Their blue receptors, though, noticed the strangeness, but they had difficulty logically processing the emotional glow they saw.“It’s throwing emotions out.” Sand-Stirrer said.

“Why would something clockwork give off emotions?” Ice-Driller asked..Again, a was sent out by the craft directed at the source of the sounds, which appeared to be originating at many points around the craft.

“I don’t know, but hydrothermal vents catch its attention.” Sand said.

“Quick, Sand-Stirrer and Thermal-Rock, get together. Sand, send a sono-picture at the same time that Thermal-Rock makes the sound of a hydrothermal vent. Then when it pings again, send back the sonic image.”

The decapods did that at the best timing they could manage. They changed the distances to appear to be perhaps half a kilolength below. Of course, their bodies showed up on the ping, but since they were imitating a sound, the general picture was cast toward the object. It was rudimentary as best, lacking all background echoes that a listener would expect from the seafloor.

The machine sped down, pushing both of them out of the way, and continued to descend. Behind it, there was a continuous coil of what seemed like dense rope.

“Amazing.” Ice-Driller muttered. Everyone, gather up all the things and let is try to bring down… it.”

“We can’t keep calling it it.” Study-Up said. Besides, we discovered it, so we should name it!”

The decapods gathered all belongings. The sonic pictures, The Overworld Stone, Study-Up's pierced research, and of course, a small net with food.

“What about the Overfin!” Sand-Stirrer said.

“But it doesn’t have any fins, it seems to have a constant siphon and ejection.” Study-Up replied.

“The Otherworld ” said Sand-Stirrer, of course, instead of the word 'swoosh' using a something kicking up a large wake.

“How about this: ” Study-Up said. It was the word of ‘it’ but visualized above the ice.

They all descended and caught back up to the object, which was still uncoiling the strange cable from its rear.

“The Over-World-Building?”

“Yes… OWB.” Of course acronyms were not directly translatable, but it was the most prominent parts of the sono-image from which one’s mind could perform the ‘connect-the-dots’ mentally and get nearly the same image from a simplified representation of sound. A two-dimensional acronym.

The descent continued and as they neared, the object's behavior changed. Instead of doing pings, the submarine played a series of sounds: undersea currents, strange chattering, the cracking and groaning of ice, and deep songs of some creature that was eerily reminiscent of a baleen shark’s call. The object shot out numeric sounds: one dot, then two dots, then three dots, all the way to ten dots.

“It can count!” Ice-Driller said. “If we can get it to follow us down to the city, perhaps then my father will be released. Perhaps war will end since we will unite.”

“Is this even a good idea?” Study-Up asked.

The object then produced more sounds, almost like the constant flowing of a dark smoker hydrothermal vent.

“What if it destroys our city, or poisons us?” Sand-Stirrer said.

“What else can we do? Leave it here for our enemies to control?” Ice-Driller replied. “Lets try to get it to follow. I have an idea.”

They descended and left the icy meltwater behind. Ice-Driller and Study-Up held on tight to the front of the net near The Overworld Stone. Behind them were the cargo netting containing the sonic pictures and the seismometer recordings. Holding fast to the back of the netting were Thermal-Rock and Sand-Stirrer. Behind them, the machine followed.

At the bottom of the ice, the craft split and a part left the back of the craft. That second object exploded as large air bags inflated, pinning the coil and the parts to the underside of the ice-shelf.

“Look at that!” Ice-Driller said.