Title: A Close Encounter With Time
Summary: Jayne, sentenced to baby-sit Serenity, encounters a strange blue box... A crossover between Firefly (Serenity) and Doctor Who (10th Doctor Era).
Rating: K for mild swearing. Subject to change.
Disclaimer: I own neither Firefly nor Doctor Who
Authors Notes: I know it's been a while since I last updated, but please keep in mind that I make no promises regarding chapters and when they'll be posted or finished. Since I can't control life I don't see much point in trying. For those who stuck with me, though, thank you for continuing to read and having such patience. Thank you to those who read and reviewed the first chapter! I truly appreciate the time you took to leave me a message -huggles-

Chapter Three

"It's more than that…" He got a stunned look on his face, "this whole city is being poisoned!"

There was a beat of nothing as the preposterous information was soaked up before Mal jammed his thumb onto the talk button on his radio. "Zoë! Get everyone back to the ship. Now!"

Zoë's voice crackled back, "Problem, sir?"

"The kind where you need to be back on this ship ten minutes ago, yes."

"On our way, captain."

Mal let the radio go. "You have some gorram explaining to do," Mal said, addressing the brown-clad man along with the blonde girl on his arm.

The man and the girl, however, paid him no mind. He raised his strange little pen shaped machine up and down and then in all sorts of odd directions and patterns before beginning to quickly walk off, away from Serenity. The girl jogged to catch up with him, and neither paid any mind to the guns and their wielders around them.

"Hold it!" Neither Jayne nor Mal were about to let the man and his trumpet just walk away. The two guns, Mal's and Jayne's, swiveled to reset on the retreating figures. "Stop!"

The man spun on his heel, his long brown coat whipping around him. "You coming, or what?" He asked, and then turned again and continued his fast walking.

"Gorram weirdos," Jayne muttered.

Mal got a funny look on his face. "Jayne, stay with the ship. When Zoë and the others get back, make sure she's sealed up and running on her own air supply." Without any other warning, Mal began to jog after the odd couple.

River allowed her gaze to be ripped from the strange blue box. She bounced up on the balls of her feet, gave her brother a small kiss on the cheek, and ran after Mal.

Simon blinked after him. "But…

Jayne attempted to sigh, but it turned into a growl. He ground his foot into the dirt, and finding that unsatisfying, he threw a punch at Serenity's hull. "Ouch." When that failed, he swore profusely with at least one word Simon had never heard before.

The two men caught each other's gaze. "Well, this blows."

Simon sighed. "Indeed."

River was ecstatic – she loved to run. She caught up to Mal within seconds and together they tagged the heels of the odd duo in front of them.

"Ah! Decided to come along then?" The man asked, never breaking his step. How he was able to run and speak at the same time without panting was beyond Mal. Unable to do the same, despite his fit state, he merely grunted in what he hoped would be assumed as an affirmative.

River, however, began to sing and apparently had no qualms about having to pause to gasp in a breath or two as they sprinted throughout the city. "Pocket full of rosies…"

The man gave her a sharp look and slowed his long legs, his little metal wand out in front of him. "The readings are getting stronger…" he said, and pulled to a halt. The girl and Mal stumbled to a stop beside him, but River bounced in place.

"Ashes, ashes, we all fall…" River continued to mutter her song quietly.

The man in the long brown coat again gave the small young woman an odd look. "You shouldn't know that song…" he said slowly, "and it's poesies, not rosies."

"Doctor?" The blonde girl looked at him, concerned. "The air?"

"Oh! Right." The metal wand flashed blue in his hands again. "This seems to be the central point of the nitrogen contamination. It is all spreading out from here."

"But, there's nothing here." Rose, who had regained her breath, threw her hands on her hips and drew her brows together.

"You're completely right…"

And, he was. The place the four had stopped at was the outside of what had once been a diner but was now long abandoned. On the corner of a seedy street, the diner façade had fallen into disrepair and only half a chair could be seen through the boarded up windows and doors. Long strips of yellowed tape ran up and down the door and were covered in the careful stamps of the Alliance's seals, but they thin paper had been broken ages ago, and no one here had seen even the backside of an Alliance agent in over a month.

"But, looks can be deceiving," the doctor drawled.

The blue stick flashed again and unable to stand being kept in the dark any longer, Mal asked, "what in gorram hell is that thing anyhow?"

The Doctor was ignoring him and muttering to himself instead. "The radiation's center… but how is it spreading…"

Rose took pity on Mal and explained. "It's a sonic screwdriver."

Mal blinked. "A what…?"

"A sonic screwdriver." She paused to mime the little piece of metal. "It's a screwdriver… that's sonic."

Mal shook his head. It could have been a golden screwdriver for all he cared. These people were completely off their rockers.

"Rose!"

The girl, who Mal had decided was even bubblier than Kaylee, whipped herself around and re-devoted all her attention to the odd man. "What is it, Doctor?"

He flashed her a wild and wide grin and shook his head a bit. "I'll tell you what it is, Rose, it's alien."

Mal's jaw dropped.

"There's no way anyone from this time or cluster of little planets could have modified it in such a complex way. The composition even had me confused for a moment or two, and that's saying something."

"Modified what, Doctor?" Rose had her arms crossed in front of her chest and had placed all her weight on her left hip. Despite the disbelieving looks (looks that were slowly turning to anger) that Mal was giving her from behind her back, the Earthling girl was not about to be swayed from getting an answer from the Doctor. This was hardly the first time he had rattled off in incomprehensible technological terms and forgotten about the less-than-advanced alien background she had. Not that she felt hindered by her lack of understanding. Honestly, she didn't much care how certain alien things worked, like the T.A.R.D.I.S., so long as they did and so long as the Doctor and her stayed together.

The Doctor's smile widened even further, regardless of how impossible that seemed to Mal.

River, meanwhile, had finished counting the bricks on all the visible buildings and had since compared the missing bricks, the damaged bricks, and the intact bricks in her mind. She had discovered the life expectancy of a brick was quite low, and also that three months ago someone had removed one entire side of the abandoned restaurant's wall and then shoddily put it back together with a different type of molder.

"Someone," the Doctor said quickly, as he always did when he had discovered something or became excited, "has taken an engine, an Alliance space type, but fairly outdated, and coupled it with a Bosh ship's atmosphere system. The Bosh are a sort of space nomads, but I've never seen anything of theirs on a planet before. In fact, it's quite taboo for a Bosh to even land on a real planet, let alone leave bits of his ship on one." The Doctor scratched at his head. "That' quite weird, actually."

Meanwhile, Malcolm Reynolds lost his patience. He was normally a very composed man and he prided himself on being able to handle himself in just about any situation. But enough was enough.

"I don't know where you folks are from or what you're doing out here in this corner of space, but let me tell you one thing: if I learn that you had me call in my crew from their first real break in over two months for some wild goose chase over fairy tales, I will not be a happy man," Mal said in a quiet and dangerous voice. "I'm a fair man, but there are plenty of men around these parts who aint."

River, who was inching towards the abandoned diner, covertly stuck her tongue out at him.

Despite Mal's menace, the Doctor only glanced at him. "No fairy tales, here, I'm afraid." Without even glancing around, the odd man strode purposefully forward, still talking, and ripped past the paper seals covering the door. "The Alliance engine supplies nearly unlimited power since it simply taps into the city's sources. The Bosh atmosphere system, a brilliant piece of design, actually, physically replaces old air with new air by taking in the molecules, scrambling them around a bit, and then shooting them back out. It takes heaps of energy to do, though."

The Doctor in the lead, the four of them walked through the dingy entrance and into the dusty room. It took their eyes a few seconds to adjust from the florescent buzz of the outside to the dank dim of the diner. What they saw, though, was two huge metal contraptions, one blue and steel and sleek, the second orange and brown and bumpy, almost like coral. It was something Mal had never seen before, and he was not shy to let his mouth hang open.

"Gorram…"

Rose swallowed. "So, if the Bo…?"

"Bosh," the Doctor supplied.

"Bosh atmosphere system is for replacing air, where is the nitrogen coming from?" She said, voicing the thought that had been in Mal's mind too.

"See, that's the ingenious bit. Someone's gone and meddled with the Bosh's work. Instead of converting carbon dioxide to a oxygen, nitrogen, and what not mix, now the system is converting everything into straight nitrogen."

"Poison," Mal spit out bitterly.

"Yes, exactly. This is defiantly sabotage."

And that was when it happened.

River coughed as the nitrogen, which was slowly replacing the air all over the city, began to fill her lungs.

tbc

This is unbetaed, so if you see anything that drastically needs help, please feel free to let me know (in fact, I would appreciate it a lot). Thank you for reading, please let me know what you're thinking and leave a review – they are very helpful and nice to get.