The House of Styx

by Derek Künsken

  THE INSIDE OF the bathyscaphe was claustrophobic, a tight cylinder of acid-resistant steel so thick that even a hundred atmospheres of pressure wouldn’t crush it. A single long couch lay inside, with the head facing a single piece of fishbowl-shaped diamond, built over years by hard-working nano-machinery in the depths of the atmosphere, where the heat and pressure helped.

  The back of the little craft was devoted to rows of small Stirling engines. They couldn’t do more than keep the inside of the bathyscaphe around the boiling point of water, so their survival suits, rated to a hundred and fifty degrees for short periods of time, had to keep them alive. Short wings on the sides of the bathyscaphe made it a small aircraft with a propeller to the aft, like a torpedo. George-Étienne pointed the nose down and they began a stomach-lurching drop.

  They were surrounded by most of the metal wealth their family owned, their last resort if they ever needed to trade away metal for medicine, but also their secret tool for going deep below the clouds to recover things on the surface. It was the most exciting, frightening thing Pascal had ever seen or done. They plummeted through the last fifteen kilometers of the sub-cloud haze, streams of vapor whipping past the front glass in the steadily heating wind. The temperature outside had risen from ninety to two hundred degrees Celsius by the time they finally broke through to the clear air below thirty kilometers. Gloomy red light showed gray mountains, old lava channels, and wrinkled volcanic plateaus beneath them.

  It was difficult to hold the Causapscal-des-Profondeurs in one place against fast winds in the lower decks, so George-Étienne had decided to turn their fall speed into flight speed and race ahead of the habitat. They would reach Diana Chasma an hour before the habitat did. Alexis would slow the Causapscal-des-Profondeurs as soon as they were away.

  “You sure they’ll be okay?” Pascal asked.

  “They’re both good boys. I left you alone for the first time at that age.”

  George-Étienne pulled up on the stick. Ailerons moved and the bathyscaphe switched from free fall to a gliding descent, racing along at three hundred kilometers an hour. They shook in the straps as they crossed columns of hot volcanic gas.

  The basaltic highlands of Atla Regio passed serenely beneath them, silvery frosts accenting the black and brown of the highest peaks. Small dark clouds of vaporized lead sulfide shone near the surface. George-Étienne spoiled the airflow over the wings, dropping their speed and altitude as Diana Chasma came into view. He pointed at something too small to see.

  “There,” he said. Pascal couldn’t see the cave any better than his father, but they knew it was there.

  George-Étienne extended the spoilers further. The bathyscaphe shuddered and the wind moaned louder. They banked, slipping to lose altitude and speed. The surface of Venus rose to meet them, until he could look horizontally ahead to see the highland peaks of the wrinkled gray coronae. A frisson of unease crept along Pascal’s spine. He’d never been close to any solid surface, and had never had mountains and rock around him. Even from five thousand meters above the bed of Diana Chasma, a weird claustrophobia crept upon him. His breath came quickly.

  “Ça va?” George-Étienne asked.

  “Oui,” Pascal said breathlessly. “Is this what it felt like on Earth?”

  His father grunted a low laugh. “Not at all.”

  Their turns tightened and the movement of the vast stone edifice beneath gave him vertigo. The clouds weren’t like this. They moved constantly, shifting from one vague shape to another, but in a way, every cloud was the same cloud. This Venus was disorientingly hard and sharp-edged. The world darkened as the mountains, and finally the walls of Diana Chasma itself, occluded horizon-light.

  It took some time to notice the quiet outside the bathyscaphe as it slowed. The wind became so soft that the creaking complaints of joints and seams sounded louder and louder. The centimeter of diamond they peered through made tiny crinkling noises. The centimeter-thick steel of the craft resounded as it heated up, magnified as if their craft were a drum head.

  At two hundred meters above the surface, they’d stopped flying. The propeller churned behind them as if they rode a tiny submarine through an ocean. The gigantic cliff face rose before them. Slightly west of them was the mouth of the cave. Their cave.

  If they cut their forward speed, they would slowly sink. George-Étienne brought the bathyscaphe nearer and nearer, and they began to notice the cross-current dragging them towards the cliff face and the cave mouth. He then turned the bathyscaphe into the current and throttled forward full speed on the propeller. Their ground speed dropped to zero and they sank, holding above a single point on the ground.

  Pascal was already bringing the first of their new modifications to bear. Out of a forward tool hatch, a cable shot out on the end of a micro-torpedo. The torpedo dragged the cable around a big, immovable boulder and then looped back to the bathyscaphe. The manipulator arms they’d installed under the craft recovered the micro-torpedo and attached the cable. Pascal’s readings said that the two ends of the cable were firmly attached to the stern and the loop had been secured under the boulder.

  “We’re good, Pa,” Pascal said. At least, he hoped they were. His father cut the throttle and the current carried the bathyscaphe along, turning it, until the cables jerked taut.

  “Sapristi,” George-Étienne cursed in wonder.“That wasn’t gentle, was it?”

  The cave mouth stared them in the face. Silt blew past them on the wind, moving as it would on an ocean current. The mouth yawned large, twenty meters across in a canted oval.

  They bobbed gently as the current washed over the creaking bathyscaphe back to front. Beyond the little window was Venus herself, naked in her gray and black basaltic glory, close enough to touch. She was beautiful and deadly, life-giving and ugly, aspects she reconciled without apparent difficulty. To each side, the bottom of Diana Chasma extended, a hundred kilometers wide, with sharp edges that rose dizzyingly beyond the angle of their diamond porthole. In the distance, on the highlands, a smudgy column of smoke arched as it rose, tilting westward. His father slapped his arm.

  “Let’s get moving,” George-Étienne said. “It’s already a hundred and ten degrees in here. The insulation isn’t as good as I thought.”

  George-Étienne used the manipulator arms to assemble a pre-fabricated cage made of the stiff, acid- and heat-resistant cable that Pascal had managed to save from the trawler they’d lost. It was built to fit the triangular probe in their photos. A tripod of powered manipulator arms would ride with it, controlled remotely from the bathyscaphe. And they used a trick Pascal had thought up. A small plate, no larger than a hand, was affixed to the end of the cage. That little patch, in the current of supercritical carbon dioxide, would drag like a drogue chute, pulling the cage all the way down to the triangular probe and keeping it oriented.

  Pascal unspooled a second cable, tied to a good high-temperature, multi-spectrum camera with a high-temperature memory wafer. In the same mounting was a radio receiver and recorder to follow the comms emissions they’d found. Between them were mounted two powerful lights, a main and a spare. They would see and record everything this time around.

  It took fifteen minutes in the gentle bucking of the current to assemble and ready their payloads. While his father unspooled the cable, letting the current drag the cage in, Pascal played out the cable carrying the camera, keeping it always five meters behind. The harsh white light showed walls of erosion-polished basalt.

  About twenty meters in, they found the first of the cave branch points that they’d inferred from the grainy, dark pictures of the first trip. This second current fed the main one, widening it.

  “We’ll call that Branch B,” Pascal said.

  First the cage, then the camera shuddered around the first bend, knocking against the walls of the eddy. All they could do was feed out the cables faster and hope nothing important had been damaged. They found the source of the turbulence and eddying, too.

  “We’ll cal
l that Branch C,” Pascal said.

  “And there’s your Branch D,” George-Étienne said.

  Pascal stopped unspooling his cable, leaving the camera in one spot in the cave as he turned its lens and light ninety degrees, and then in a complete circle, to survey the edges of the cave. The diameter of what he was going to call the Main Branch was about forty meters across now. The current flowed at about twenty-five kilometers per hour here.

  It was an enormous river of super-critical carbon dioxide. Pascal briefly wondered where all of it was going, and even why it didn’t noticeably deplete Venus’s atmosphere. But that was absurd, a failure of human reason to fully absorb the size of Venus. She was nearly the size of the Earth, and her “ocean” covered the entire surface. This cave was big to him because his entire home would fit in here without touching the walls, but this was just a small river. And Venus blasted thousands of tons of carbon dioxide into the atmosphere from volcanoes and hot vents every day. Her immense ocean of an atmosphere could never run dry, and she was too big ever to understand.

  They paid out more cable. The cage danced ahead in the camera view, shaking worse as it approached the wall, where the current pulled ferociously. The smoothness of the eroded surface prevented the carbon fiber cage from being abraded or smashed, and it went out of sight.

  Pascal unspooled ten meters of cable, fast enough for the camera to be swept around the projection without even touching it, jerking to a halt in the eddy beside the cage. Stray currents tugged at them, but for the most part, the cage and camera hung in the becalmed carbon dioxide. Just beneath lay the dusted outline of one of their mysteries.

  “Your show, Pa,” Pascal said. “How fast can you get that scrap packed?”

  “Watch me,” he said. “I’ve been retrieving stuff in storm winds since before you were born.”

  “Ha!” Pascal said. “Old man.”

  George-Étienne got the manipulator arms to spider-walk themselves out of the bottom of the cage and searched along the wall of the big, dark eddy until he found a fissure that had not been sanded smooth by erosion. It stuck one manipulator there and reeled the whole cage down into even calmer parts of the eddy, near the silt-covered triangle. A sense of impending discovery filled Pascal. His father’s breath rasped in his earpiece, around moments of breathless concentration.

  The manipulators ended in three flat fingers, which could also be configured like a propeller. George-Étienne turned one of them on and the twirling finger blades pushed the hyper-thickened atmosphere of Venus like water. The new current stirred pebbles and sand and silt, clouding the eddy, obscuring their view. Gradually, though, the silt rose high enough to be drawn away by the main stream. Pascal pointed the light and camera down, zooming the view.

  George-Étienne whistled in appreciation.

  The clearing silt revealed a flat brown-gray isosceles triangle, four meters long and about three wide. Raised lumps studded the base segment, like the stomata on trawlers and rosettes, with a few located symmetrically on its forward edges. A large glassy lens capped its front apex.

  “What the hell did the Russians or Americans send down here?” George-Étienne said.

  “It’s not a wing,” Pascal said. “There’s no curvature to make an airfoil. It’s just flat. That doesn’t make sense if they wanted it to explore Venus’s atmosphere.”

  The bathyscaphe creaked again. “We’ll think at home,” George-Étienne said.

  The manipulator arms opened the cage. In the meantime, Pascal turned to the radio receiver and looked quickly at the data.

  “The radio source is still deeper in the cave system,” Pascal said. “Something is being transmitted up, a repeating burst every point-two-two-three seconds, like a code.”

  George-Étienne grunted, directing one manipulator arm to gently lift the nose side of the triangular probe. More silt clouded into the eddy. He moved the edge of the cage nearer.

  “Maybe it’s a distress signal, or a hail looking for a confirmation,” George-Étienne said.

  “A distress signal wouldn’t be coded.”

  “Depends how secret this probe was,” George-Étienne said. “This thing was obviously damaged. Maybe its flight recorder or even its CPU broke and it was carried deeper by the current.”

  Pascal was sweating now. One hundred and thirty degrees in the bathyscaphe. The old Stirling engines were cooling poorly now, and his suit couldn’t keep him at normal body temperature for long. He drank from the plastic straw in his helmet.

  “The power of this signal is in the megawatt range,” Pascal said, “even after reflecting off who knows how many twists and turns in here. Why would they overpower a transmitter that much? What’s its power source? This probe had been collecting dust for years, maybe decades.”

  George-Étienne stopped slipping the edge of the cage under the probe. He had a look in his eye.

  “In the early days, a lot of long-mission probes were powered by plutonium and uranium,” he said. “Do you know how valuable that is?”

  Pascal felt himself sharing his father’s grin. This was big. An antique probe sent by one of the early space-faring powers. A coded radio signal. Radioactives they could salvage for power. It was like a lost treasure.

  “As soon as you finish caging that thing and you don’t need the light, I’ll start sending the camera deeper,” Pascal said. “I’ve got another four hundred meters of cable. If it’s plutonium or uranium, then maybe a power plant from a bigger facility or probe is down there.”

  George-Étienne slipped the cage base under the triangular probe and gently lowered the top of the cage. The manipulator arms closed the clasps and latches.

  “I’m going to start pulling it up,” George-Étienne said. “Go ahead with the camera.”

  “One problem,” Pascal said. “I think we’ve run out of time.”

  It was a hundred and forty degrees inside the bathyscaphe.

  “Duvieusart didn’t spend a lot of time on the surface, did she?”

  “Forty minutes,” George-Étienne said. “I’ve made some improvements, but forty minutes.”

  “We might not even have time to bring up the probe,” Pascal said.

  “I’m spooling as fast as I can.”

  “Pa, how risky do you want to play this?”

  “What do you have in mind?”

  Pascal did some quick calculations, showed them to his father and explained his plan to stop the rising temperature for maybe fifteen minutes.

  “Viarge!” George-Étienne swore. “It’ll hold?”

  “It’s a big boulder.”

  His father looked at the massive piece of basaltic stone perhaps four meters wide and tall that Pascal indicated ahead of them. Then he considered the numbers. His face was awash in sweat. Probably forty degrees in his suit already. Venus was slowly cooking them.

  “You don’t refuse to eat when you sit at Venus’s table,” George-Étienne said finally.

  Pascal unwound the cable at the stern of the bathyscaphe, the one binding them to their boulder. The bathyscaphe approached the yawning cave mouth in slow jerks. Twenty meters. Ten.

  Neither of them needed to mention that if the cables didn’t hold, they’d crash somewhere on the inside of the cave.

  The diamond porthole darkened as the edge of the cave yawned past them. The bathyscaphe shuddered in the current. No big changes outside yet. Pascal turned on the exterior lamp, lighting the black surfaces. They advanced another twenty meters and came to the end of their cables.

  The temperature had dropped here. The current was moving so fast that the pressure dropped too, which cooled the carbon dioxide flowing past them. The little shell around them vibrated gently, but held. The temperature inside the bathyscaphe was one hundred and forty-one degrees, but had stopped rising.

  “Calvaire,” his father swore. “Never thought I’d be under the surface of Venus.”

  “Dropping the camera further in. We’ve probably got another ten minutes.”

  Pascal u
nspooled more cable for the camera and lamp. The image bobbed and spun as it was recaptured by the main current. The pressure and temperature around the camera kept dropping. Three hundred degrees. Two hundred and fifty. Then the rushing current started behaving like a gas again.

  “Five minutes,” George-Étienne said.

  The view from the camera bumped and rocked and occasionally spun. At one turbulent point, the manipulator arms nearly lost their grip and dangled from one set of fingers. The other arms didn’t manage to relatch until George-Étienne pulled the whole bundle through the turbulence of one of the turns. The cage and probe smashed hard.

  Pascal’s camera twirled in the churn, down another turn in the cave. Not all the rock was the same. Basalt, soft with heat, eroded more quickly than a second type of rock Pascal was seeing, but not recognizing. Magma had probably covered this whole area, including some older rocks. The decades and centuries of current had carved where it could cut most easily. Who knew how many bends there were?

  The spinning camera emerged in the next eddy, trapped there until he paid out more cable. He didn’t have much left. The pressure had dropped a lot around the camera, and the temperature too, but the current flowed at over two hundred kilometers per hour. The twisted cable took a while to slowly unspin itself and one of the bumps had jarred the camera angle ninety degrees to the side, so the unwinding produced a lighthouse view of this new space.

  “What’s that?” George-Étienne asked.

  Pascal had been staring hard at his screen, trying to figure out just that question despite the spin. The cave walls were dark and distant, but a sixth of each arc showed a region of salt and pepper silt. Under the silt were triangular shapes, eight or ten or even twelve. The eddy was quite large and the camera angle wasn’t very good. The silt was not as deep here, and some of the triangular shapes were only lightly dusted. The camera slowly ended its rotation and stared at the shapes. The closest ones looked exactly like the one George-Étienne was hauling up. They were all the same size. Some had cracked outer casings and even jagged holes.