A strange virus

The lights in the TARDIS flashed, the engines groaned, as it whirled through the vortex. Bill clung onto a railing; she couldn't quite keep the grin off her face. Even though every flight seemed like the TARDIS was about to crash, it never stopped being a thrill.

When the activity faded Bill hurried up to the console. The Doctor flicked a final few switched before turning, looking like a magician on the cusp of finishing his act. He grinned at her.

"So where are we now?" Bill said.

"Human colony," the Doctor said. "Few centuries on from your time. Want to take a look?"

"Always!" Bill said. She beamed.

They hurried over to the door; the Doctor opened it, and Bill ran out first. Smiling to himself the Doctor followed, locking up behind them while Bill walked forwards, looking around at the whole new world.

Differences were large and small. The sky was blue, but tinged a different colour, slightly greener; there were also four different moons in the sky, one glaring and one little more than a wisp in the daylight. The world's Sun was a little larger, the air smelled slightly different; a hundred small things made sure there was no way to imagine this was Earth.

The buildings all seemed pre-fabricated, one floor blocks constructed from single sheets of either plastic or metal. Elsewhere even more hastily constructed areas were visible, shelters made of little more than sheets pulled over a few sticks to make a roof with no walls. Tables, scientific equipment, chairs all out in the open.

That was when the first naked woman ran past, blushing and hastily trying to get across to a different building. Bill blinked.

"Uh..."

There were a few people milling around, rather than making a frantic dash for it. By the scientific equipment out in the open, peering at microscopes or computer read-outs, all dressed in vaguely practical looking clothes.

And then there was a sudden flash of more skin past the open-air lab as a nude woman ran by again, followed by two others.

Come to think of it, the people working at the lab did all seem to be men. What was...

"Doctor," Bill said slowly. "Not that I don't appreciate it, but why did you bring me to a planet where all of the women are..."

A red face peered out a window at them, bare shoulders visible at the bottom of the frame. Bill tried not to stare. The Doctor, meanwhile, was frowning.

Ok, so he didn't know either. That was rarely encouraging. It certainly didn't seem like they were intentionally nude, judging by how they kept hiding or sprinting when they did have to move, but if it wasn't intentional why weren't they getting dressed?

"Look! Look, it's a miracle!" someone suddenly shouted.

Bill hesitated, and in seconds four men had run over to them, leaving their labwork behind. Bill took a step back.

"What is?" the Doctor said.

"Your friend," one man said; "She's not infected. Who are you? Did the distress signal reach a ship already? We were expecting it to take days."

"We, uh, were passing by," the Doctor said. "The signal got a bit garbled. Just in case, how about you explain everything as though we never got it?"

The man, a tag sewn into his spacesuit-looking garb identifying him as 'Phillips,' nodded eagerly, apparently too relieved to question the Doctor's story. He led them back to the open air lab, passing under improvised pillars to rest in the shade.

"It started weeks ago," Phillips said. "Maria, uh, that's my daughter... we don't know what exactly, but something happened to her. Her clothes just vanished, no matter how much she tried to get dressed. And then it spread, kept spreading; by the time we realised it was somehow contagious, the whole camp was... None of the women have been able to get dressed for three weeks. They're doing what they can inside, we're working on it too, but our work's not had any luck. At a guess it's some kind of virus, but we've not been able to isolate any cause, any transmission vector. But you're here, you don't seem infected."

"Wait," Bill's eyes went wide. "We, uh, only just got here. What do you mean infected?! How long does it take to..."

"Near instantaneous," Phillips said. "It's why we didn't have time to quarantine anyone. That and we didn't expect nudity to be catching; the moment one women met another it was passed on. That goes for men too, but men seem to just be carriers. It's only been women who've been affected."

"Should we, uh..." Bill glanced at the Doctor. "Is it safe to be here if there's an infection?"

"Oh, perfectly safe," the Doctor said. "You heard him, instantaneous. TARDIS provides protection against diseases, you wouldn't want to go walking around alien environments, or even just your past and future, without it. The number of viruses that could get past the TARDIS's defences, well, they're incredibly rare."

Bill breathed a sigh of relief. Her clothes feeling like they were prickling was probably just her imagination then, just nerves. The Doctor turned back to the colonists.

"I'm the Doctor, this is Bill. Here to help," he said.

"A Doctor?" Phillips said. "Medical?"

"Sometimes," the Doctor said.

"That's good. Hopefully you know why your friend's immune," Phillips said. "This is what we've discovered."

Phillips tapped something on the screen; a file filled with jargon popped up, glimpses of base codes and DNA sequences and all manner of technical details appeared on it. The Doctor frowned, peering closer.

Knowing full well she was out of her depth where that was concerned, Bill started looking around instead. The colony only seemed weeks old, judging by how fresh and new everything was. Half the inhabitants being too embarrassed to be seen probably wasn't helping them all that much.

Hopefully the Doctor could sort things out.

Her eye was caught as a darker skinned woman ran from one building to another; Bill glanced after her. Ok, normally she preferred naked woman to be much more happy about how and why they were naked, but a view was a view. So long as the Doctor was right about the TARDIS protection.

"Fascinating," the Doctor said. "An ontological virus, no direct means of detection. The only way to tell is observation of the symptoms. Possibly still curable, but it'd take work. Maybe extend the TARDIS bio-field, it's kept Bill safe."

"Ahh!"

"Or maybe it just delayed things," the Doctor swiftly amended.

Bill suddenly felt her clothes prickle a lot more, her dark jeans, her top, her underwear all suddenly flaring against her skin. And then, an instant later, there was relief; no more tingling, no more prickling.

And also, she noticed looking down, no more clothes. Bill's eyes went wide, and she cried out as she realised everything had suddenly been put on display. Her shirt dissolved to nothing, most of her jeans vanishing in an instant. Everything below mid-shin was intact, but the denim was useless for modesty's sake. The pitiful rings of fabric slumped into her trainers.

Above them was just bare, brown skin, two perfect legs leading up to her exposed pussy, and her rounded ass, each cheek shifting slightly as Bill jumped from shock. Above that was her abdomen, and then her modest tits, extra-dark nipples adorning each, all topped off by her thoroughly flustered face.

She shrieked, and hastily crossed one arm over her chest, the other trying to hide her pussy. It felt thoroughly inadequate, especially it was just Phillips and the Doctor she was hiding from; the colony stretching out behind her had an unobstructed view of, well, her behind.

"Doctor!" she squealed, suddenly finding herself nude before the colony.