Title: Half Sick of Shadows (Chapter One)

Author: E.A. Week

E-mail: eaweek at hotmail-dot-COM

Date of publication: May 2012.

Summary: The barren planet Gossan holds a powerful secret, one that is somehow connected to River Song's release from prison. Can River and the Eleventh Doctor defeat the Papal Mainframe, or will they become its prisoners for all eternity?

Category: Doctor Who. Eleven/ River.

Distribution: Feel free to link to this story from another web page, but please drop me at least a brief e-mail and let me know you've done this.

Feedback: Letters of comment are always welcome! Loved it? Hated it? Send me an email and let me know why!

Disclaimer: Copyrights to all characters in this story belong to their respective creators, production companies, and studios. I'm just borrowing them, honest!

The story title is shamelessly stolen from the ballad "The Lady of Shalott," by Alfred, Lord Tennyson.

Datclaimer: This story is rated M for sex, language, and mild gore/ violence.

Continuity (PLEASE read this): This story follows after the events of Doctor Who, season six. I assume that this story will be rendered apocryphal/ alt-universe/ moot/ irrelevant once Steven Moffat decides to continue telling the story of the Silence. This is my version of how events might play out.

Chapter One

A bloodcurdling scream woke Marissa from her uneasy sleep. She bolted upright, grabbing her torch, playing it around the inside of the canvas tent. Her father was already on his feet, stumbling outside.

"Haviva!" he shouted.

Marissa shot out of the tent behind him, swinging the powerful beam of her torch around the desolate, rocky landscape. In the distance, she spotted a human figure, a black silhouette against the gray dawn sky.

"Father! There she is!" Marissa sprinted ahead of her father, calling out, "Havivia! Wait! Come back!" Her strong legs carried her toward a rocky outcropping. "Haviva! Please, don't do it!"

She reached the foot of the outcropping, a pile of rock as high as a small building. Marissa knew she'd never climb it fast enough. Behind her, she could hear Father's labored breathing as he raced to catch up with her.

Above their heads, Haviva stood, long hair blowing in the wind. For just one instant, Marissa saw the look on her face—lost, terrified, tormented. She stared down at Marissa, their eyes meeting for a long, unendurable moment. Then Haviva opened her arms wide and fell.

(ii)

They burned her body in the same canyon where they'd cremated the others, dousing the broken corpse with fuel and setting it alight. Then they stood at the top of the gorge, watching the flames consume her flesh before they threw rocks and gravel down, covering the charred skeletal remains as best they could.

"It's just us, now," Marissa said.

"I know," Father replied.

(iii)

They huddled in the cave that night after dinner, both of them staring into the meager fire, saying nothing. Marissa didn't know what she feared more: dying the way the others had died, or being the last one left alive in this wasteland. And if she didn't, for whatever perverse reason, succumb to the madness that had claimed the others, she would die of hunger when their food ran out. There was plenty of clean water on Gossan, but nothing edible. Marissa wondered what was worse: a slow death from agonizing starvation, or a quick death on the rocks.

The next morning, Father went to the wreck of their ship, taking stock of their food supplies and sending another distress signal. Marissa had long since given up hope that anyone would hear them. Technically, nobody was even supposed to be on Gossan, and she doubted any ships would pass by close enough to pick up their emergency call.

While Father worked, Marissa nosed about the darkened ship—the areas that were still intact—staring at the things they'd brought along: books, prayer rugs and shawls, chanting beads, talismans of their faith. Those things looked so sad now, relics of a time and a place irretrievably lost. Marissa was so homesick, it was like a physical pain. She wanted to go home—more than anything, she wanted to see her home world again.

Father looked up from the ship's computer, which he could run sparingly on auxiliary power. "What's that?"

"What?" asked Marissa, distracted. "That noise? It's the wind."

A moment later, they both heard it: an indescribable mechanical grinding noise. For one electrifying instant, Marissa's eyes met her father's, then they both bolted for the exit, racing outside the hulk of the ship.

The last thing either of them expected sat on the boulder-strewn slope: a bright blue box with a flashing light on its top. Marissa couldn't imagine a more incongruous object in this barren desert of stone.

"This is how it starts." She clutched Father's hand. "The madness, the hallucinations, the things nobody else can see."

Father said, "I see it, too."

A door in the box opened, and a woman of middle years emerged: small, strong-looking, moving with supreme confidence. Her hair was fair and very curly; her clothes consisted of a drab gray-green sleeveless tunic, plain gray trousers, and utilitarian black boots. She shaded her eyes from the sun, looking all about.

A moment later, a man emerged behind the woman. He was tall, very thin, bearded, his hair dark brown, shot through with startling streaks of silver. He wore dark trousers and a long olive green coat.

"Do you see them?" Marissa whispered.

"Yes," Father said, his voice shaking. "They're real."

Marissa sprinted toward the newcomers, waving her hands. "Here! We're over here!"

The man and woman began climbing down the slope. "Was that your distress signal?" the woman called. "We picked it up and homed in on it."

"Yes!" Marissa shouted. "Yes—our ship crashed. We've been here for almost a year." Before she could say anything else, she burst into a torrent of tears.

(iv)

Several minutes passed before Marissa could speak coherently. The woman held her tightly, rubbing her back. "There, there, it's all right," she said.

Father told the strangers what had happened.

"I'm called Tremaine, and this is my daughter, Marissa. We were traveling from Euclase to Symestine, and our ship's engines began to fail. We had to make an emergency landing here on Gossan. We've been sending distress signals every day for nearly a year."

The man said, "Why did the engines fail?"

Tremaine spread his hands wide. "We never could determine what went wrong. Everything was in excellent working order when we left the spaceport. I've been running the ship's computer on auxiliary power; I've run every diagnostics program we have, and so far I've turned up absolutely nothing. It was like the engines just died."

"You crashed?" the woman asked, peering over at the old starliner.

"Let's call it a very rough landing," Tremaine said dryly. "The hull was damaged—even if we had enough power, we'd never get her safely into orbit."

"How many of you are there?" the man asked. "Just the two of you?"

Tremaine said, "There were sixty of us, initially. Marissa and I are the only ones left."

"Did the rest die when the ship landed?" the woman asked, her forehead wrinkling.

"No," said Tremaine. "No, they—well, it's a long story. You haven't even told us your names, or what that blue box is."

"I'm called the Doctor, and this is Dr. River Song," the man said. "That blue box is our ship."

"Does it have room for two more passengers?" asked Marissa.

"Loads of room!" the Doctor laughed. Sobering, he asked, "What happened to everyone else?"

"Come with me," said Tremaine, his voice heavy with weariness. "Over here. It's a story best told sitting down."

(v)

"Over here" turned out to be a cave about a half-mile from the ship, where Tremaine and his people had taken shelter, setting up neat canvas sleeping tents in a circle around a fire that they'd contrived by burning fuel in a steel canister. A number of folded tents leaning against the cave walls bore mute testimony to the people who'd died.

"I only wish you'd come soon enough for Haviva; you might have been able to help her," Tremaine said, beginning the conversation in haphazard mid-thought. "She was my cousin. She resisted the madness longer than any of the others, but in the end, even she succumbed. We cremated her just this morning. Please have a seat." Tremaine gestured to some overturned gray packing cartons, standard issue on most starliners: they were durable and extremely lightweight. River and the Doctor took seats. Marissa served food while Tremaine poured out beakers of water.

"At least the water here is clean and plentiful," he said wryly. "We'd never have survived this long without it."

River observed the man and the girl. They were dusty, grubby, exhausted-looking—and thin. No doubt they were rationing their food stores to last as long as possible. It must have been difficult for Tremaine but torment for Marissa, who looked as though she were still growing. She was a strapping lass, easily over six feet tall, broad through the shoulders, her hands very long, her feet rather large. She'd gotten her looks from her father, a tower of a man, just a few inches shy of seven feet. White hair and a white beard framed a large, craggy face, his eyes set deep in his face, quiet and watchful.

River put Marissa's age at about sixteen, her babyish face incongruous on that powerful body. Her hair was long, dark blonde, falling in two loose braids over her shoulders. Both father and daughter wore a tunic and trousers of fabric that looked hand-woven, the trousers dark brown, the tunics dark red. When Tremaine passed River her beaker of water, River observed a striking geometric tattoo on his right wrist. Marissa bore a similar mark on her left.

River took a sip of water. "Are you Moolotites?" she asked. Father and daughter jolted, and River said quickly, "It's all right. We're not from the government. I'm an archeologist—I've studied religions."

Tremaine relaxed, though his eyes held a wary expression, one that River suspected had come from decades of persecution. "Not everyone is so accepting," he said.

"Is that why you were traveling to Symestine?" asked the Doctor. He glanced down at his wristwatch, tapping the face. "Oooh," he said sympathetically. "This is a bad time for Moolotites on Euclase."

"We lived in our own community on Euclase," Marissa nodded. "It wasn't always easy, but people would at least leave us alone. Then the new government came to power, and they began restricting our activities more and more, and they took away all our protections, and people became more and more hostile. They wouldn't leave us alone. That's all we've ever wanted—to be left alone." She hiccuped back a sob. "They hate us—why do they hate us so much?"

River and the Doctor glanced at each other. "There's never a rational reason for hatred," River said. "Especially religious hatred."

"We had no choice," said Tremaine. "People were dying—our neighborhood had become a prison whose walls were slowly closing in on us. Perhaps three dozen of us escaped, and we joined up with Moolotites from other cities. We pooled our resources, bought the ship, and hired a crew who promised to bring us to Symestine—there's a Moolotite community on Symestine, and religious refugees are welcome."

The Doctor said, "Was there any sign your ship had been sabotaged?"

River added, "How trustworthy was your crew?"

Tremaine said, "We had full confidence in our crew. They weren't Moolotites, but it's difficult to believe they'd have scuttled the ship deliberately without making some provision for their own escape."

"They were as upset and frightened as the rest of us," said Marissa. "Maybe even more so, because they couldn't tell what had happened to the ship's engines. Maybe that's why they were the first—"

"What?" asked the Doctor.

"The crew were the first to succumb, starting with our navigator," Tremaine said. "About two weeks after we landed. At first we thought she was under duress from the fear and panic. She was having nightmares—horrible nightmares. And then she began having hallucinations. She saw things nobody else could see. She wasn't able to tell her visions from reality. At last she ended her own life to be free of the torment."

"Seeing things?" asked River. "Did she say what?"

Marissa offered, "Things from her past. She thought she was responsible for the engine failure. It was like she was haunted by guilt. She'd just scream and scream because she thought we'd all died and she was surrounded by corpses. One morning we woke up to find she'd thrown herself from a high ridge during the night."

"Early morning," said Tremaine heavily. "They all ended their lives just before dawn. Most of them jumped—there's certainly no shortage of high places around here. One used the ship's fuel to self-immolate."

"And it spread from the crew to the passengers?" the Doctor asked. "Everyone?"

"One by one," said Marissa, her eyes brimming. "As if something was singling them out, finding weaknesses, isolating their minds, and then destroying them from within."

River jolted a bit, exchanging a swift glance with the Doctor. She asked, "Were everyone's visions the same, or did they see different things?"

"Why is that important?" asked Tremaine.

The Doctor said, "It's not unusual for a—a telepathic entity to prey on individual fears and doubts. Long-buried phobias and insecurities are magnified and turned against the person, until they're driven mad."

Marissa shuddered. "Everyone's nightmares and visions were different."

"Have you explored much?" asked the Doctor. "Did you find anything? Disturb anything?"

Tremaine shook his head. "Apart from the ship's landing, no. We've collected water, made our camp in this cave. There's nothing to disturb."

River pointed to the yawning darkness at the rear of the cave. "What's in there?"

"Nothing," said Marissa. "We only explored it a bit. It goes back a fair way, but we didn't want to waste our batteries."

Tremaine said, "And Moolotites don't believe in exploiting resources—we've always lived as lightly as possible."

"Still," said the Doctor, "you might have disturbed something, just by being here."

"'Something?'" echoed Tremaine. "What kind of something?"

River said, "Some planets, even stars, are sentient. They have a consciousness, an awareness. And they don't take kindly to strangers, to anyone they perceive as a threat."

Distressed, Marissa said, "We've done nothing!"

The Doctor said, "A planetary entity wouldn't know that. It exists on a vaster scale than you can even imagine. It wouldn't think the way you do; it might not have language; it wouldn't reason the same way as you."

"It was an accident we even landed here," Marissa said. "We weren't—"

Tremaine broke in, "Given the circumstances, I'd say the wisest course of action is to leave the planet immediately." He asked the Doctor, "Can you take us to Symestine in that blue box?"

"I can take you anywhere," the Doctor said. "But Dr. Song and I are here for personal reasons, and we'd like to have a look around before we leave."

"Aren't you afraid of disturbing… it?" asked Marissa.

"We've only just arrived," the Doctor said. "You said it took a fortnight before anyone was affected. That buys us some time."

"We've been here almost a year," Tremaine said. "We might not have as long. Marissa and I are the only two left. Sooner or later, one of us will succumb."

River asked, "Doctor, why don't they wait in the TARDIS? The ship will shield them, and they can wash up and rest."

The Doctor asked Tremaine and Marissa, "What do you think?"

Marissa said doubtfully, "In that blue box?"

The Doctor hopped up to his feet, grinning, "Get your things," he said.

(vi)

They were speechless at first, then the questions began.

"No, no, not really enough time right now," the Doctor protested, holding up his hands. "This is when it'd be good to have someone like Rory on board—he was always so good at explaining everything. Dr. Song and I need to look at the back of that cave. Tremaine and Marissa, why don't you two have a lovely wash and kip for a bit? River, show them the way, would you?"

River led their two flummoxed guests to the bathrooms and showed them a spare bedroom where they could rest.

"How long will you be gone?" asked Marissa.

"There's no telling," River said. "It depends on what we find. But you'll be safe in the TARDIS. You can shower or bathe, and sleep for a while. There's clean clothes in the wardrobe, if you want to change. You both must be exhausted."

"I'll feel better when we're on Symestine," said Tremaine.

"You will soon," River promised. "The only thing we ask is that you not touch anything in the console room."

At last, Tremaine relented. "All right," he said. "But Dr. Song—our lives are in your hands."

"We'll be back," River said. "You have my word on that. If there's anyone who can learn what happened to your crew, it's the Doctor."

(vii)

"What's all this?" asked River when she got to the console room.

"Caverns," the Doctor said. "You told me Professor Candy was planning to explore caverns." He looked up, grinning. "So, let's beat him to the mark."

River sorted through the equipment with a professional eye. "Good," she nodded. "We're going to need to wear something lighter and more practical."

"Check the wardrobe," the Doctor said. "There should be gear from when I took Rose and Jack down the Orinoco."

Within thirty minutes, they were suited up and ready, clad in lightweight, khaki shirts and trousers. The fabric was durable and tough, but so light that they could swim in it without extra drag; it would also dry quickly. On their feet they wore thin, flexible, rubber-soled shoes that would protect their feet but still enable climbing. They carried lengths of climbing rope, ascenders, carabiners, quickdraws, and a variety of belaying devices—everything they'd need for a descent through underground caverns. About their foreheads, they wore powerful miners' lamps, and they carried additional torches on their climbing harnesses. Everything would be carried in waterproof packs. The Doctor had also located face masks and small oxygen canisters.

"How much air will those give us?" asked River as they carried everything down the hill toward the cave.

"About three hours' worth," the Doctor said.

Inside the cave, they divided up the gear and strapped the packs onto their backs.

"Are we good?" asked River, switching on her miner's lamp.

The Doctor switched on his own lamp. "Geronimo," he said, bounding down the length of the cave. "Feel that draft of air—can you believe Tremaine's team was on the planet all this time and never had a butcher's?"

"Can you blame them?" River asked. She hurried alongside the Doctor, keeping pace with his long strides. "Is the planet sentient? I can't feel anything unusual."

"It's alive," the Doctor confirmed.

"Can you communicate with it?" asked River.

"I'd rather not take that chance just yet," the Doctor answered. He tapped his forehead. "Shielding things for now, just in case."

River realized she'd done the same thing without even realizing it—probably as soon as they'd left the TARDIS, an unconscious Time Lord reflex.

"That's how Tremaine's people were affected," she said. "Their minds are so open from all their meditating, they have no way to defend themselves from psychic attack."

They'd walked far enough now so that they'd lost sight of the cave's mouth behind them. The ground sloped steadily downward, and the air grew cool, damp. River cast her light about the cave walls: black, unremarkable. Here and there, water ran down the stone in tiny rivulets.

"Gossan's something of an enigma," she said, drawing on her course readings from memory. "It has a good atmosphere and gravity, plenty of water and sunlight, and yet no life forms have evolved beyond lichens and a few microscopic aquatic species. All the conditions are here for life—on any other world, by this point in its history, the planet would be teeming with plants, animals, insects—but there's nothing here at all. It's almost sterile."

"It does make you wonder," the Doctor said, pausing for a moment to examine some loose rubble. "Extrusive igneous rock," he said. "Same as outside. No variety."

River said, "It's like something's inhibiting normal evolution, normal development."

The Doctor glanced at her and put a finger to his lips. Comprehending his wish for caution, River nodded.

She was glad of their lights when the cavern came to an abrupt end at a stone wall. The way forward lay at their feet: a gash in the floor. River played her light down the well, but it only illuminated a few meters. Beyond that lay pitch blackness.

She uncoiled her longest length of kernmantle rope. "Only one way from here."

They didn't rush their preparation, using a spring-loaded camming device to secure their ropes to a pair of boulders nearby, rocks large enough to support their combined weight. River tugged on climbing gloves, then checked her harness and the Doctor's.

"I'll go first," she offered when they were ready.

"I should," the Doctor began, but River cut him off.

"Sweetie, I went to school for this, and besides, I've been training since I was a child."

"Seriously?" the Doctor asked. "The Sil—they taught you how to rappel?"

"Rappelling, rock climbing, land missions, air missions, aquatic missions—" River touched his nose. "There was no telling where you'd show up or what skills I'd need to bring you down." After a quick kiss for good luck, she said, "I'm versatile. Besides," she winked, "ladies first." She ran the rope through her hands, planted her feet against the rock wall, and began to lower herself into the abyss.

(viii)

Their chief worry—that they wouldn't have enough rope to complete the abseil—proved unfounded. There was still plenty left when River's feet touched the bottom. "I'm down," she called. A few moments later, the Doctor dropped beside her.

They unhooked their torches from their belts and took a look around. This cavern was much the same as the one above, the ceiling about a meter over the Doctor's head, the rock more of that unremarkable black stuff.

"These are naturally occurring caves," River said, "probably formed during tectonic shifting or ancient volcanic activity. They weren't formed by water—the walls are too rough—and they weren't dug out mechanically, either. The walls are too irregular."

"Were you expecting something different?" asked the Doctor.

"Professor Candy was hoping we'd find remains of an ancient civilization."

"Sorry to disappoint him," the Doctor said. "There wasn't one."

"There wasn't one, or just not one that you found?" River taunted.

He shrugged. "Is there a difference?"

River made a face. "Which way should we go?" she asked. From where they stood, they could follow one of three tunnels.

The Doctor wet his right index finger and held it up, turning around in a 360-degree circle. He pointed. "That way."

River withdrew a stick of waterproof chalk from a pouch on her belt and marked the tunnel entrance. As they progressed along the passageway, she made a couple of additional marks, arrows pointing back the way they'd come.

"So, you studied Moolotites," the Doctor said, breaking the pervasive quiet.

"I studied every religion," River said. "I used to inhale books whole, the more obscure, the better. Moolotities have been around for eons, though they're long past their greatest age. It's an old faith, and as other belief systems evolved, Moolotism didn't change, and its adherents were regarded with some suspicion."

"What do they believe… or not believe?" he asked, as if testing her knowledge.

"That their gods have no names, no physical entities, no dwelling place," River said. "Worship is done outdoors—they consider it sacrilege to build temples. Each adult has a prayer rug, a shawl, and a string of beads—they're said to carry their own temples with them, wherever they go."

"And this put them at odds with…?"

"Galenians, mainly," River said. "Devotees of the father-god Galen and his consort Galena. They're actually a Moolotite off-shoot, and Euclase was their principal planet. They humanized their gods, gave them names, attributes, personalities, feast days, and made up complicated stories about them. They built temples—extravagant temples, some of them."

"Becoming very rich in the process," the Doctor said.

"Naturally," River agreed. "And this was a more attractive religion—less time praying out in the elements on mats in uncomfortable positions; less time meditating. The Moolotites see divinity everywhere, so they rarely interfere with their environments. The Galenians were less scrupulous about exploiting resources—they were quite clever, actually, about developing mythology to justify pretty much anything they wanted to do."

"Hmm," the Doctor said, scanning the walls with his sonic screwdriver and looking at the readings.

"The Galenian population grew and grew, until the Moolotites were a minority on their own planet," River said. A thought occurred to her. "Do you think there's a connection with what's happened here? Were these Moolotites…" she paused "…afflicted because of their faith?"

"Hmm? No," the Doctor said. "Anyone who couldn't shield their mind would be affected. But notice how the crew—the only non-Moolotites—were first."

"The Moolotites' faith was protecting them?" asked River.

"Grounding them," the Doctor said. "Giving them something to believe in. But as time passed and the hope of rescue faded, even the faithful began to doubt. And that weakened them."

"Tremaine and Marissa are the last because they also have faith in each other," River realized.

"Exactly."

River shone her light down the tunnel, hoping to see something, anything, to break the monotony of the dark cavern walls. "Sadistic," she said under her breath.

"Yes," the Doctor agreed. "Taking them one at a time, eating away at their perceptions of reality, not killing them, but making them end their own lives, sowing yet more fear and doubt among the survivors. Yes. Sadistic." The Doctor looked down the tunnel. "Good word."

River fought back a shiver. Peering ahead, she said, "Doctor, can you see light?"

"Torches off," the Doctor said. They both switched off their torches. "Now these." The Doctor switched off his miner's lamp, and River did likewise. She braced herself for the unnerving total blackness. Instead, they both saw a faint luminescence in the distance.

"Ah-ha!" the Doctor said, sounding satisfied. They switched their miners' lamps back on. "Knew it!"

They picked up their pace, River keeping the beam of her torch playing across the ground before them, lest they encounter another crevasse. But the floor of the cavern—smooth, packed dirt—remained unchanged. The glowing light ahead continued to grow until it illuminated the tunnel enough for River and the Doctor to switch off their miners' lamps and for River to switch off her torch. They hurried the last few meters to the mouth of the tunnel, stopping short in astonishment.

River said, "Oh, that's stunning!"

The Doctor said, "Looks like we're going to get wet."

(xiv)

The underground cavern was enormous, a veritable lake, stretching out beneath the roof, its surface smooth, unbroken by so much as a ripple, black as obsidian. Overhead, the roof of the cavern glowed with light, thanks to a thick layer of magnificent phosphorescent crystals.

"At least there's something down here besides black rock," River said.

The Doctor scanned the lake. "There," he said, "can you see it, there?"

River withdrew a small pair of compact field glasses and took a closer look. "It's another tunnel," she said. "I don't think the water goes into it, though—there's a bit of a shoreline. We should be able to swim across to it pretty easily."

"If we can get down to the water," the Doctor said.

River was uncoiling another length of rope. "That's the easy bit," she said. "Getting across the lake without developing hypothermia will be trickier." From the pouch on her waist, she withdrew two small squares of something that looked like chewing gum, each wrapped in a piece of waxed paper. "Eat this. It'll adjust your metabolism so your body will retain heat for two hours."

The Doctor ate the small square, grimacing. "Tastes like… like strawberry flavored paste."

"It's not haute cuisine; it's just supposed to keep you alive," River smiled. She used her chalk to mark their position in the stone wall.

Their abseil down the cliff face went without incident, and before they knew it, they stood on the stony lakeshore, where the black water lapped noiselessly against the rocks. River ran a quick test of the water quality. "It's safe," she said. "I wouldn't drink too much of it, though. It's not as cold as I'd expect—just under 15 degrees Celcius." They transferred all their gear into the waterproof packs and inflated air pockets in the sides of the packs.

"Push the bag ahead of you, and if you get tired, turn onto your back and kick," River instructed. "We'll save the oxygen canisters in case we have to do any underwater work."

She entered the water first, climbing carefully over the rocks, wading up to her waist, and pushing off. "It shelves deeply," she called back to the Doctor. "The temperature's all right for now." The water wasn't what she'd call warm, but thanks to the metabolic stabilizer, it didn't feel as icy as it normally would.

They kicked out into deeper water. After a few moments, River suggested the Doctor turn onto his back so that she could take the lead. Halfway across the lake, they switched places, River turning to kick on her back and the Doctor pushing his pack ahead of him. They swam in silence to conserve energy, not rushing to avoid leg cramps.

River enjoyed staring up at the ceiling of glowing crystals, which shimmered in hues of pearly white, delicate pink, sky blue, and palest lavender. Near her head, she felt the quiet wake created by the Doctor's kicking. The water smelled clean, and River ventured a tiny sip, rolling the liquid over her tongue, confirming that the lake was uncontaminated by any pollutants. The water wasn't stagnant at all, perhaps fed by underground springs.

When River heard the Doctor's voice, she lifted her head out of the water.

"We're almost there," he said.

River turned onto her belly again, pushing the pack ahead of her and kicking alongside the Doctor. Before them, the far shore appeared, a long strip of rocks where the roof of the cavern sloped down. River could see the tunnel entrance easily. She checked her waterproof watch: they'd been swimming for nearly an hour.

Ten minutes later, they felt the steep lakebed beneath their feet, and when the water became shallow enough for them to find purchase, they clambered with care up the rocks.

"Phew," laughed River, taking hold of her right ankle to stretch her quadriceps muscles. "There's a workout for you."

While she stretched, the Doctor deflated their packs and withdrew two small bottles containing a mixture of water and electrolytes. He handed one to River and downed the other himself. Then they strapped on their climbing harnesses and miner's lamps. Their wet clothes would dry as they walked.

"We've been gone nearly four hours total, including the swim," River said. "I hope we find what we're looking for soon—we don't have enough food and water to stay down here forever."

The Doctor peered down the tunnel. "The source is nearby," he said, his voice ominous. "We're getting closer to it."

They proceeded with more caution now. After a few meters, the phosphorescent light behind them began to dim, and the tunnel closed in around the two time travelers. They switched on their miner's lamps first, then the torches. This tunnel was much the same as the others, but it felt closer, darker, more sinister. River began to long for daylight, and she tried not to think how long it would be before they'd escape the bowels of this lifeless planet.

Although River didn't possess a full Time Lord's senses, she still enjoyed a heightened awareness of psychic influences, the faculty that humans called the sixth sense. She'd begun to grow cognizant of something around them in the rock walls, something alive, capable of thought and emotion. Their footsteps, quiet as they were, still sounded too loud to River's ears. She glanced at the Doctor, meeting his gaze. He gave a slight nod, acknowledging that he had perceived the same things, but saying nothing aloud. River was grateful for her ability to shield her mind, also for her immense faith in the Doctor. She often felt she could walk unscathed through Hell itself as long as she had the Doctor at her side.

The scent was so subtle that she didn't at first notice it, until the Doctor stopped short, head craned forward, nostrils flaring.

"Burnt sugar?" River murmured.

"No… more like…"

"…bitter almonds," they said in unison.

River shrugged out of her backpack, removing the oxygen canister and looping the face mask around her neck. The Doctor took the same precaution. They moved forward, sniffing the air. River kept one hand on her oxygen mask, ready to slip it up at a moment's notice, staying alert for any signs of dizziness or nausea or light-headedness—the classic symptoms of cyanide poisoning. As they moved forward, the bitter almond smell grew stronger, but they had no difficulty breathing.

"There," the Doctor said, pointing to the right. Further up the tunnel, illuminated by their lights, was the dark outline of an archway.

They slowed, approaching the doorway on silent feet. River went first, flattening herself against the wall before she took a quick look through the archway, casting the light of her torch all around.

A multitude of faces stared back at her, gray-white, distorted, black eyes large and hollow. No mouths—just eyes. Long bodies, black-clad, the middle digit of each hand enlarged and grotesque.

River let out a brief shriek. Silents. The underground cavern was full of Silents.

To be continued…