The Doctor floated adrift in space. The wreckage of his TARDIS was spinning in random directions for several miles around him. The Doctor rotated slowly as his momentum from the blast carried him. The sun warmed one cheek while ice crystals formed on the other, then sublimated away as he spun the other direction. The planet Centeros passed through his view, a gorgeous blue and green tennis ball from his perspective.
"Well," the Doctor thought. "This is a bit of a situation." He'd had the foresight to take one last breath, and now he closed his eyes to protect them from the vacuum, willing his hearts to slow to almost nothing. He entered a trance while he contemplated how he came to be here.
Only a few hours earlier, the Doctor and Romana landed on the quiet streets of Centeros. Romana exited the TARDIS and unbuttoned her coat. She turned and addressed the Doctor as he stepped out of the police box. "Now, why do you suppose the TARDIS took us here?"
"That depends entirely upon where here is," the Doctor said. He locked the TARDIS door and turned to take in the view.
The late afternoon sun hung behind a low haze. Massive brick chimneys, presumably attached to factories, could be seen behind the housing of the neighborhood they had landed in.
The Doctor breathed in deeply, and bounced on the balls of his feet. "Gravity close to standard, high oxygen content, smells of coal smoke and gaslight. You know, I think we've arrived during their Industrial Revolution. One of my top ten, as far as revolutions go."
Romana smirked and adjusted her hat. "Shall we have a look around?"
The two went down the cobblestones until they reached a junction with a larger street. Parallel to the new street ran a series of railroad tracks, beside which sat an early-model automobile.
"Internal combustion engines?" Romana observed. "Isn't it a little early for that?"
"High oxygen content, remember?" the Doctor replied. "Fires would start easily and spread quickly. They must have made understanding combustion an early priority. The thing that impresses me as early, is the architecture. Did you notice the creativity of the house design? The park, just over there? The abstract sculptures on the street corners? This is a planned city, with an emphasis on art and architecture. You don't see much of that until post-scarcity, which they clearly haven't reached. I rather think I like these people."
Romana looked around again. "What people, exactly?" She was right. They heard sea birds in the distance, but there was no sign of people, or even activity.
The Doctor remained optimistic. "Taller buildings in that direction suggest a city center, and the tracks lead that way too. Let's follow them and see where they go."
They walked along a sidewalk, with the street on one side and the railroad tracks on the other, for nearly an hour, never seeing another soul, before they spoke again.
"Doctor, have you considered the possibility that this is a dead planet? It isn't normal, how still and quiet it is. No children out playing, no traffic on the rails, no one heading home from work. Maybe we should start heading back to the TARDIS." Romana said.
"Mmmm," the Doctor said in his deep baritone, "I have noticed. Have you noticed the lights coming on in the windows of those apartments ahead?"
Romana squinted. "That's not just the sun on the windows?"
"I've been watching them come up as the sun went down. In either case, we'll know for sure before long."
They got to a spot where a second set of tracks crossed a bridge over the one they were following. The sun had nearly set behind them, and the shadows grew long, but Romana spotted a shape laying near one of the bridge supports. "Doctor, is that a person?"
It looked like a man with masses of dark, curly hair and a long unkempt beard, huddled in a long tweed coat. "Perhaps he can tell us where everyone has got to." The Doctor quickened his steps and crossed the street toward the man. "I say, good fellow, I'm dreadfully sorry to wake you, but I hope you can help us. We're looking for whoever is in charge here."
The figure didn't move at the sound of the Doctor's voice. "Careful, Doctor. Something's not right," Romana said, hurrying to catch up.
The Doctor stopped and bent over the man. "You're right, Romana. And it's him." The Doctor gently rolled the man over on his back, exposing his face. His eyes were staring, and his anguished face was covered in purple splotches.
The Doctor covered his face with his scarf, and Romana took a step backward. She opened her mouth to say something, but stopped as the sound of an engine approached.
Headlights illuminated them, and the Doctor stood up. A flatbed lorry with wooden rails pulled up, and the doors to the cab swung open. Soldiers appeared from the back of the lorry, as well as both sides of the cab, all wearing what appeared to be surgical masks. They all pointed weapons at the Doctor and Romana. "Show us your travel papers!" the driver demanded.
Romana sighed and put her hands up. "New worlds to visit, check. Engaging mystery to solve, check. Strangers pointing guns at us… I must be traveling with the Doctor."
The Doctor sensed light flashing behind his eyelids, and he cracked open his eyes. A piece of his console was passing nearby, and it caught the sunlight as it turned. "Ahh. The temporal regulator," he thought. He moved slowly, to conserve energy, and formed a loop in the end of his scarf while he unwound it from his neck. He tossed the loop, and managed to snag the regulator on the first attempt.
He reeled in his scarf, and held the regulator to his chest, closing his eyes again.
"Hello, I'm the Doctor, and this is Romana," he said with a broad smile, entirely ignoring the guns.
"The doctor?" the driver said. "At ease men." The soldiers lowered their weapons. "Then, why are you on foot?"
"Well," the Doctor said. "I find it's the best way to see the situation on the ground, don't you?"
"Well, you're needed at HQ, so hop aboard. Your assistant too," the soldier said.
"Oh, I'm not actually his —" Romana started.
"Shh now, lab tech Romana, the sergeant has more important things to worry about, and we're in a hurry."
Romana gave the Doctor a withering look, and he smiled in return as the two were helped onto the bed of the lorry. It made a U-Turn and headed toward the tall buildings. One of the soldiers handed the Doctor and Romana masks, which they put on.
None of the soldiers in the cab wore uniforms, they simply had badges sewn onto whatever clothing they were wearing. "What can you tell me about the situation so far?" the Doctor asked.
"It's grim, sir. They think it's something in the air. If you breath it in, you can get it. Purple spots, trouble breathing, then within days, death."
"What percentage of the people who show initial signs end up dying?"
"One hundred percent, sir."
They lapsed into a grim silence for the rest of the ride.
The lorry pulled up to a parking lot cordoned off with sandbags and barbed wire. A couple armed guards stood watch as the crossing-arm was raised, and the lorry went through. They were surrounded on three sides by a building announcing itself as the 'Ellen Preston Primary School and Library'. The soldiers filed out, and Romana and the Doctor followed.
"This way," the sergeant said. He lead them into the school through open double doors. The corridor inside was lined on both sides camp beds. Patients moaned and twisted in the beds, trying to get comfortable.
The sergeant turned toward the library, and walked quickly past the plague victims, paying no heed to their cries. He held open one of the double doors at the end of the corridor, and beckoned for them to hurry through.
"It's cold in here!" Romana said as she entered.
The sergeant closed the door behind them. The interior seams of the door were lined with rubber strips, keeping most of the air from circulating into the hallway. "Dr. Pentagrast's theory is that germs spread faster in the heat. That's why they cause a fever in the infected. We keep it cold to control the spread of the disease."
"I see. But, how did you get it cold in here?" the Doctor asked.
"Sorry, sir, I'm really just a sculptor. You'd have to ask Pentagrast how the machine works."
All the bookshelves in the library had been removed, or else they were laying down in rows with stretchers packed tight on top of them. Mosquito netting was draped over tent frames, covering each row of the moaning, suffering patients.
The sergeant led them between two rows toward a group of tables set up on the far end of the room, where two men were standing, discussing something in the papers scattered there. The sergeant came to attention behind the two men. "Dr. Pentagrast, sir!" he said with a salute.
The two men turned. The older one, with a shining pate surrounded by candy floss whips of white hair, removed his glasses. "Oh, please stop saluting me," he said, but he raised his own hand in a tired salute until the sergeant snapped his off.
"The doctor you requested has arrived with his assistant."
"I'm really not his —" Romana started.
"I'm the Doctor," the Doctor interrupted, coming forward to shake both their hands, "and this is my assistant, Romana. How do you do?"
Romana rolled her eyes and sighed. "We were just asking how you keep it cool in here," she said.
"Oh, yes. The air compression-expansion-circulator. Don't worry, we'll come up with a better name later. My assistant Simon made my idea real. Perhaps you could explain it, Simon?"
"Well, it's nothing, really," Simon said. "Dr. Pentagrast needed a way to cool the patients. Everybody knows that expanding gasses feel cooler, so I thought, 'What if we expanded gasses in one chamber, then let the gas escape while we condense air in a second?" It's a bit like a two stroke engine, just without the combustion."
"That's actually quite impressive, Simon, and might I say it works wonderfully? I'm quite glad of my coat and scarf."
"Yes, very clever," Romana said. "Now, perhaps you can tell us how we can help?"
Dr. Pentagrast put his glasses back on. "Yes. Well, we've given up on our antibiotics, they are having no measurable effect, but I'm convinced that the cause is still a germ, perhaps just many times smaller than a bacteria. Smaller than we can see in a microscope." He motioned toward a microscope set up on the table with a candle and a mirror providing light to it.
"May I?" the Doctor asked.
"Please."
The Doctor peered into the microscope and adjusted the focus. "This is a patient's blood sample?" he asked.
"Yes. Taken an hour ago."
"How long after symptoms started to show?"
"Two days."
"And how long between initial symptoms and death?" Romana asked.
"It depends," Simon said. "Between five days and a week."
The Doctor stood up. "I can't see anything abnormal in there."
"Yes," Simon said. "We were just working on a lens configuration that might increase magnification significantly without taking up more space. Could you help with that, Doctor?"
"I believe I could at that, but I'll need the instruments in my cabinet. I wonder, sergeant, could your men fetch it for me? It's a big blue box, you can't miss it. I left it over on Seaborne Avenue, a few miles past where you found us."
The sergeant looked to Dr. Pentagrast, who nodded. "Go," he said.
Romana nudged up beside the Doctor. She leaned in close and said, "They've discovered antibiotics already?"
"Yes, I caught that too. And before electricity," he said, pointing at the candle lighting the microscope. "Another anachronism?"