"It's coming back around!" El shouted, as she and the Doctor ran down the quickly cracking corridor.
The Doctor looked over his shoulder, as the giant alien creature rammed the glass again, the already large crack splitting even wider, as more water began to drip in.
"That glass won't take much more punishment!" The Doctor worriedly pointed out, as he and El came to the door.
Fiddling around, trying to get the door open, the Doctor pointed at the control panel with the sonic screwdriver, pressing the button, before both of them ran through, the sliding metal door clamping shut behind them.
"No glass…" The Doctor let out a breath of relief, flopping against the metal door of the windowless tunnel. He looked through the small window on the door and blinked. "Oh, that is not good."
"What is?" El asked.
"Welp, that corridor is flooded now." The Doctor replied. "Well, actually, our big friend out there has completely ripped the roof off, but never mind that…"
"We can't get back to the TARDIS." El finished, shaking her head.
"Don't worry, I'm sure we can figure something out." The Doctor told her, standing up.
"So, what is this place?" El asked, looking around, as the Doctor entered a junction with more transparent viewports.
"A sub-aquatic community." The Time Lord answered, hands clasped behind his back, as he looked around with a proud smile on his face. "See, while global warming does manage to get fairly bad, you lot find a way to reverse it eventually. It's not hopeless… nothing ever is, as long as there's someone still alive. Anyway, when the Earth's oceans rose, seventy-five percent of the surface landmass was covered, so what does humanity do?"
"What did they do?" El asked, allowing the Doctor to string the conversation along.
"They move!" The Doctor threw his arms out and twirled around, gesturing at the base they'd found themselves in. "Great undersea cities! Entire civilizations moving underwater! Some stayed up there, mind you, but you know how the old song goes; Darling it's better down where it's wetter."
El frowned, looking around. "Doesn't look like a city."
"Well, that's because this one isn't." The Doctor explained, gesturing for El to follow as they walked through the corridors. "Poseidon Eight. The farm of the future."
El looked up at the glass. "Where's the shark?"
"It's not a shark, it's a Zaralok."
El was taken aback slightly. "A what?"
"A genetically-engineered intelligent lifeform." The Doctor answered, sonicing through the next door. "The Valky Clan of the planet Shakara created them as living weapons to fight in an undersea war. Armored, fast, smart, and hungry. But the Zaralok turned against everybody and ate them all. God only knows how one wound up on Earth."
"Can I…?" El trailed off, holding up a hand to refer to her powers.
"The Zaralok can handle the massive crushing pressure of the ocean floor, and it just ripped through reinforced titanium alloy supports and Pyrex like it was tin foil." The Doctor retorted as they proceeded along the next section, sector E/F if the signage was to be believed. "Your powers would only give it a little tickle. Still," The Doctor looked out into the water, the Zaralok swimming far away. "He's not coming back around for another go. He must think we're not worth it, or he gave himself a bangin' headache trying to ram the corridor. Blimey, these people love their codelocked doors." The Doctor remarked, bypassing the next one.
"What is this place?" El asked.
"A storeroom or a loading dock I'd imagine." The Doctor replied. "Ah, yep, see?" The Doctor pointed to the airlock door. "Your standard deep-sea transport extra-hardened against water pressure."
"Water what?" El repeated.
"Pressure." The Doctor repeated, as they continued forth. "The farther down you go in water you have all these tons and tons of water bearing down on you from all sides, a bit like air pressure, actually. But go down deep enough and the weight of the water can start actually crushing big things. A normal car on the seafloor for example would be crushed like a tin can."
"Which is why we can't go back to the TARDIS." El guessed.
"Yep." The Doctor replied, "Holding my breath would be easy enough, but even I can't handle undersea pressure. And I would suggest using your powers to create a bubble surrounding us, but the strain to maintain it would be ridiculous."
"Right…" El nodded. "So, you said farm. Farms grow things. What do they grow here?"
"You know, standard farm fare." The Doctor answered, leading her along. "Food, mostly. Sea sprouts," He pointed to a little patch of the vegetation growing outside, "Good source of iron. Oh, sticky mushrooms," He gently tapped one with his foot. "Not grown intentionally, but still, they thrive in dark, damp areas like this. And brine oil." He knocked on a barrel. "They scrape this off the seafloor and use it to help keep their machines running. Combine that with water purification systems to make sure the people inside have safe water to drink and you've got a perfectly self-sustaining undersea community. It's actually easier to live in a place like this rather than in space. Harvest oxygen from the water and you've got air too." The Doctor glanced at El. "My Ninth self did it for a couple of weeks. Not out of necessity or anything, I was just bored."
El nodded, and looked up, gulping. "Dad, it's coming back!"
"Oh, of course it is!" The Doctor grumbled, pulling her along. "Thankfully, we're here!"
"Where!?" El questioned, as the Doctor began trying to sonic his way through a large blast door unlike the rest.
"Access to Poseidon Eight's command centre!" The Doctor replied. "If there's any people left, they're going to be in there!"
The blast door opened, revealing a man on the other side. "Quick, inside!" He gestured them to enter, as the Zaralok rammed the tunnel.
"Woo, blimey, that was close." The Doctor breathed. "The Doctor, El, you?"
"Martin Flannigan." The red-haired man spoke with a thick Irish accent. "Doctor? There's a hospital ship up top? Did you come down in a bathysphere?" He sounded desperate, which, looking at the state he was in, made sense. He was very thin, typical of surviving off of what little crops he could've scavenged himself, diving suit hanging loosely off his form.
"Bath… sphere?" El looked to the Doctor.
"Don't worry about her, she's still getting used to the pressure." The Doctor told Flannigan, as he sent something to El. 'Deep-sea exploration craft. He thinks we're from the surface.'
"Oswald must've got an SOS out." Flannigan continued. "Maybe Jones will let me in Poseidon now that there's medical help."
The Doctor raised an eyebrow. "Why do you need medical help?"
"The sickness!" Flannigan replied like it should have been obvious. "It's taken everyone on the base… That's why Jones won't let me in. Oswald has put the base on lockdown." He sighed. "I was working a harvester out on the prairie. That creature attacked us… killed Pat, the base leader. And now Jones won't let me in because of the quarantine. I've been stuck here two days."
El frowned. "Jones sounds stupid."
"It's a computer." Flannigan replied, shooting a look over his shoulder to the octagonal computer bank in the center of the room, an optic on the front.
"Ah, so this must be it here then." The Doctor pointed, approaching the camera. "Hello there, Jones, I'm the Doctor. What's this I hear about you not letting in my good friend…" He turned to the man, expectant.
"Flannigan."
"Flannigan?" The Doctor turned back to the computer. "He says you won't open the doors because of the quarantine. Well, like I said, I'm a Doctor. Let me in, I can help."
"Poseidon Community is on lockdown." Jones replied in a synthesized, stuttering voice. "Quarantine must be maintained to safeguard the staff of Poseidon."
"Ah, yes, I knew you'd say that." The Doctor clasped his hands behind his back. "But, see, you're not safeguarding the staff, are you?"
"What do you mean?" The computer inquired.
"Martin'll eventually starve to death in here." The Doctor elaborated. "His food supplies will rot faster than he can eat them. And like I said before, I'm a Doctor, I can cure everyone inside, but only if you let me in."
The lights on the computer banks blinked.
"And, I bet you're fitted with the Laws of Robotics as well…" The Doctor guessed.
"The laws of robots?" El inquired.
"Rule one, don't allow a human to come to harm through action or inaction. Rule two, obey all instructions given by humans, unless they are to harm another human. Rule three, protect your own existence unless it requires harming a human." The Doctor explained. "And right now, it's breaking rule one."
"But Poseidon Community is on lockdown." Jones stated. "I cannot open this door."
The Doctor frowned, eyebrows knitting together. "…You're a class 14 Heuristic Analysis Machine, aren't you? With Nexus Prime as standard?"
"Correct." Jones confirmed.
"And they have you guarding door?" The Doctor incredulously questioned. "That's hardly an optimal use of your talents. Why, I'm surprised performing functions that primitive hasn't driven you rampant."
El looked to the Doctor. "Rampant?"
"It's when a computer too smart is given tasks too primitive to utilize its resources properly." The Doctor explained. "It literally drives itself to insanity to keep from being bored. Which is understandable… I've been in that position a time or two."
"…That is not a wholly inaccurate assessment." Jones admitted. "I do have considerable skills which are not being utilized at this time."
"Oh, really?" The Doctor leaned on Jones's computer bank. "Like what?"
"Well… The other day, I solved the Anghelides Equation, just to see if I could." Jones confirmed, playing a little MIDI snippet of fanfare.
"That's brilliant!" The Doctor honestly replied. "Did you use the Kessler Chart?"
"No." Jones answered. "It does not account for the four-dimensional drift. I formulated a new paradigm. It took 14 hours."
"Oho, well done, Jonesy!" The Doctor complimented.
"Thank you." Jones replied, sounding like it would have been smiling.
"Now, see, computer as smart as you, we should be able to come to a sort of compromise." The Doctor said. "How about this: You release the manual override, and we'll open the door instead, not you."
"…I would not have to open the door myself?"
"Nope." The Doctor confirmed. "No breach of programming here. Scout's honor." The Doctor bobbed on his heels. "How about it? Does that work for you?"
"It's an acceptable, logical solution." Jones replied. "Releasing the override for you now."
A little panel on the wall slid down, revealing a metal lever. Grasping and pulling it down, the other blast door slid open.
"Open sesame." The Doctor smiled in satisfaction. "Thank you, Jonesy."
"You are welcome, Doctor. It has been most enjoyable to speak to someone who understands me."
The Doctor winked, tapping the lens of Jones's camera. "I always was attracted to the smart ones." He replied, before walking to the blast door, gesturing for El and Flannigan to follow.
"…I'm not calling her mama."
The lift stopped, and the doors slid open, allowing the three access into Poseidon Eight's command centre.
"Oswald, Dana…" Flannigan sighed in relief as he laid eyes upon the two people standing in front of a Christmas tree. Oh, so it was Christmas. Huh.
The two turned around, one of them an Asian woman in a medic's uniform, the other a bald Caucasian man with a grey goatee and wearing a diving suit.
"Martin!" Dana breathed.
"We'd thought you'd been killed!" Oswald stated in surprised awe. "Merry Christmas, for what it's worth."
"When you put Poseidon into quarantine Jones wouldn't let Martin through." The Doctor explained. "But, then again, that's what happens when you have one of the smartest machines humankind has ever produced doing the work of a 1984 PC. Rather like putting Einstein on checkout. Going to get grumpy and play up."
Oswald's eyes narrowed as he looked to the Doctor. "Who are you?"
"He's a Doctor." Flannigan spoke for the Time Lord. "There's a hospital ship up top."
"But, there isn't any hospital ship." The Time Lord pointed, smiling widely. "You've got me instead! You couldn't wish for a better Christmas present!"
El cleared her throat. "And I'm El. Just El."
The Doctor's eyes narrowed inquisitively as he looked Oswald up and down. "You're not looking too good, Ozzie…"
"Get away from me." The man hissed, slapping the Doctor's hand away.
Dana placed a calming hand on Oswald's shoulder. "He's just trying to help."
"Bingo!" The Doctor pointed. "Well observed! Who are you?"
"Dana Tanaka." The woman introduced herself. "Poseidon's medic. Also the one in charge of leading the research about the sickness."
"Ah, yes, this mysterious 'sickness.' Creative name, that." The Time Lord huffed a little sarcastically. "Tell me everything you know."
"It kills the red blood cells in the body." Dana explained. "Sucks the oxygen right out of them. We've confined non-essential personnel to quarters for the moment to prevent it from spreading while we work out a treatment, but… nothing's working."
Oswald's eyes narrowed as he focused on something. "If he's not from a hospital ship, where did he come from?" He shook his head, scowling. "There's too much weird stuff going on around here."
The Doctor opened his mouth to try and make his case, when the lights suddenly died, and El yelped, grabbing the Doctor's side, as Flannigan screamed as well.
"Martin?" The Doctor asked. "What are you scared of?" The Irishman didn't respond, the Doctor getting a sinking feeling in his being as he registered the presence of a billion other microscopic minds… lots and lots of lifeforms. Tiny, feral minds, all working together towards a singular goal. To consume.
The lights returned, and Dana gasped in horror, covering her mouth, taking a step back from the skeleton on the floor.
"Martin!" Dana cried.
El looked to the skeleton covered in shredded cloth, then to the Doctor. "What's going on? What happened to Martin?"
The Doctor swallowed, gesturing with his head. "That's him there."
El looked back, then shook her head. "No, but… he was just standing there?"
The Doctor reached out, gently flipping a scrap of the suit over, revealing it to be Martin's ID tag.
"What…" El took a step back, horrified. "What did this?"
"The Vashta Nerada." The Doctor replied, turning to her. "'The Shadows That Melt the Flesh.' They live on just about every planet in the universe."
El gulped. "Here too?"
"Yeah." The Doctor confirmed, turning back to the skeleton. "…Nearly every being in the cosmos has an irrational fear of the dark. Except it isn't irrational… it's the Vashta Nerada…" The Doctor clasped his hands behind his back.
El shuddered, going to the Time Lord for protection. "Never turning the lights off ever again."
"The ones on Earth are normally docile, they only feed on small animals and roadkill like squirrels." The Doctor explained. "They know that if they start eating on things big enough it'll bring the wrong sort of attention to them. But this? This is something else. Something more feral or actively malevolent. Something alien… And I bet that Zaralok outside has something to do with it."
"…It started with the flash." Dana muttered.
The Doctor's head snapped to her. "Flash? What flash? Tell me."
"Two days ago." The woman explained. "It lit up the seabed like a bomb had gone off. Then that… creature appeared, the sickness started, the shadows…"
"Hm… another crack in time?" The Doctor rubbed his chin. "Or maybe just a teleportation caused by someone desperate enough they didn't care who they shouldered the problem onto next…"
"I have to evacuate this base." Oswald resolved.
"Good plan, bad idea." The Time Lord patted him on the shoulder. "Life pods. Lots of dark corners. Your people will be dead before they hit the surface, if they even live long enough to see the launch. Plus, you don't want to take an incurable disease back to the rest of civilization."
"We are on emergency reserves." Oswald replied, speaking slowly like he was talking to a child. "Once that goes down, we're all dead anyway!"
"Or," The Doctor replied, "I can get your reactor restarted, and since she's a pretty clever gal, put Jones in charge of running it so not only does she have something to do, the light will last long enough to get the rest of this problem sorted. Come along, El." The Doctor grasped her hand, leading her back to the lift. "You two, stay out of the shadows." He warned as the doors began to shut. "And don't even think about getting in those life pods!"
Oswald scowled as the Doctor and El disappeared behind the lift.
