Characters/Pairings: John, Sherlock, Basil, David, no pairings
Warnings: excessive cute?
Spoilers: Everything. All of it is fair game. Spoilers, ahoy.
Disclaimer: Sherlock and related characters and settings are the property of the BBC. Sherlock Holmes was created by Sir Arthur Conan Doyle. Basil of Baker Street and related characters and settings were created by Eve Titus (based of course, on the writings of…Sir Arthur Conan Doyle, who is a bit like Rome in this particular fandom map) and popularized by Disney in the film The Great Mouse Detective. No money changed hands and no copyright infringement is intended or implied.
Author'sNotes: I have to admit, this is based much more on the Disney film than the books (which I have never read).

I am partly writing this to prove to myself that I still can, since I wrote a rather soul-crushing short for the meme a few days before I wrote this piece. But I write fluff, dammit! Dark!fic just doesn't suit me.

It all started with the cat. John would swear to that for the rest of his life. Sherlock wasn't planning on keeping it, of course ("Oh, are we responsible pet owners now?" John asked him when he brought it home. "Ugh. Dull," was Sherlock's detailed and complete explanation.), but apparently there was something about this cat's particular habit of sicking up that was relevant to Sherlock's current case ("Sherlock, this is cruelty. Feed the poor thing properly or I'll kidnap it away from you." "I'm not feeding it improperly! This happens no matter what it eats!").

So the cat stayed, eating perfectly healthy cat food from clean dishes, not loosing weight, with a clean bill of health from the local clinic, sicking up all over the flat. Sherlock solved the case two days later ("There wasn't a crime at all, John! Why did this case turn out to be so dull when it seemed so interesting?" "I'm sure Harold Jones is sincerely sorry he didn't die interestingly enough for you."), and they were looking for a good home for the vomiting cat when Sherlock called John over to examine one of its offerings.

"Sherlock, I know you're bored, but I really draw the line at investigating cat sick," John said from his chair.

"But surely it isn't ordinary for there to be tiny violins in a cat's digestive tract?" Sherlock replied from behind the sofa (the cat had taken to hiding before sicking up, no doubt because it hated them both).

"What?" John asked, twisting around.

Sherlock withdrew his hand and there—on his quite sensibly latex-gloved fingers—rested a tiny violin and bow. Both thoroughly disgusting, of course, but looking exactly like a miniature version of Sherlock's own instrument.

John blinked at them for a moment and finally said, "I don't suppose they…work?"

Sherlock scowled at the tiny instrument. "I'm afraid that even if they did, they won't now." Even so, after cleaning up the latest mess, Sherlock did wrap a few jewelry tools in gauze and clean the tiny little instrument up as much as possible before removing all the strings from the violin and bow and neatly organizing it all for examination.

The bowstrings went under the microscope in the kitchen and were pronounced to be made of cat hairs. "Cat whiskers, to be precise," Sherlock said, staring in shock at the minuscule bow. The strings of the violin were nylon and the violin itself, was apparently totally functional. "The pegs turn, the fine tuner turns, it's a perfect miniature. I think this violin does work, John," Sherlock concluded in shock. "Or, did, anyhow. Before that tiny grey monster ate it."

"So…what?" John looked at the ruined little violin curiously.

"I couldn't say," Sherlock shrugged. "I wish I knew who made it."

"I wonder where the cat found it."

They received a phone call from someone who was looking into becoming a responsible pet owner that afternoon and the cat (and a warning about its anti-peristaltic habits) went off to a new home the next morning. The tiny violin went into a tiny box on the mantle over the fireplace and John mentally closed the Mysterious Case of the Minuscule Violin, thinking that was the end of the matter.

More fool him.

He was awakened that night by an astonished yell from Sherlock that dissolved into angry shouting and then a loud thud. He leapt out of bed, snatching up the cricket bat he kept by the door and wishing Sherlock's habit of filching his gun hadn't required him to so thoroughly hide it as he bolted down the stairs in nothing but tracksuit pants.

He burst into the living room to see Sherlock, on the floor, yelling at a…creature…which was trapped in an overturned glass bowl on the floor. Another creature of similar description had apparently tied his flatmate's shoelaces rather impressively together, causing him to trip (no doubt, the cause of the thud).

Realizing they were not shortly to be murdered by Moriarty's hired gang of particularly noisy ninjas, John tossed the bat on the sofa and plucked the creature now dashing nimbly up Sherlock's leg off of his flatmate's trousers.

It was a mouse. A sandy-brown mouse with perfectly calm hazel eyes, who apparently had very thin fur because it was wearing, of all the astonishing things, a jumper and a pair of denim trousers.

It also bit rather impressively down on his hand.

"Oy! None of that, you!" John said, shaking the mouse.

"Then put me down!" the mouse demanded.

John blinked. He looked down to Sherlock. "Am I still asleep?"

"A spectacularly meaningless question, given that if you were dreaming, characters in your dream could hardly be trusted to reliably inform you of it," Sherlock replied, busily trying to unknot his shoelaces.

"I must be awake. Dream-you is always much more surreal," John muttered, moving to his usual chair.

Sherlock blinked. "You dream about me?"

"I hate to interrupt, but you still haven't put me down," the mouse in John's hand broke in. "I'll bite you again if you don't, don't think I won't."

John glared at it, about to deliver a scathing response before realizing he was on the verge of arguing with a mouse. In what he felt was an impressive show of restraint, he opted for sitting down. "Sherlock, why are there talking mice in our flat?"

"Given the impressive digestive capacities of the cat recently in residence, there shouldn't be mice of any description in our flat," Sherlock agreed. He peered into the glass bowl where a mouse with black fur was irritably glaring back through the green walls of his prison.

"You still haven't put me down," said the mouse in John's hand.

John sighed and laid his hand on the arm of the chair before opening it. The mouse walked (on two legs!) off his palm, shook himself out as if his fur had been rubbed the wrong way, turned and said, "Thank you. Now then, my name is Doctor David Dawson. Could you kindly release Basil from the bowl?" He gestured with his front paws as if they were hands.

"Or what? You'll tie my shoes up again?" Sherlock asked.

"I doubt your nose would thank me for doing it a second time," Doctor-David-Dawson-the-mouse said, looking Sherlock steadily in the eye.

John could see his flatmate was somewhere between bursting out laughing and getting out the science equipment, but he did comply. The black mouse raced out from under the bowl, swarmed up the chair and ran over to David-the-mouse on two legs. "Are you alright, David?"

John took this opportunity to note the dark-furred mouse appeared to be dressed in a fashionable black turtleneck and khaki slacks. He moved his hand up to rub his head. This was still all a bit much.

"Fine, Basil," David said, to answer the question. "So much for the secret, though."

"Never mind about that," Basil replied. "Shame we'll never find my violin, though, I suppose."

Sherlock started. "Your viol—oh." He narrowed his eyes at the two mice, just as Basil narrowed his eyes back at the two humans. Then the two simultaneously burst out laughing.

"What?" David demanded of Sherlock and John of Basil, in unison.

"Don't you see, John?" Sherlock laughed. "They're us!"

"Us, but humans!" Basil finished.

"What?" David said.

"This man," Basil said, gesturing to John, "is clearly former military, with a rather impressive wound on his shoulder, obviously acquired while in service, probably in either Afghanistan or Iraq."

"Heaven save me, there's two of them," John breathed in surprise.

"And, he works at a local surgery, as the identification cards in the hall suggest," Basil went blithely on.

"Oh," David said.

"Meanwhile," Sherlock said, taking up the tale, "Basil here clearly routinely runs chemistry experiments as a hobby, judging by the staining on the tips of his paws and a slight acid burn on his…wrist. He also plays violin, given the calluses on his left paw, and is in routine contact with law enforcement, as indicated by the police identification card he dropped on the floor here."

"You brought it with you?" David hissed at Basil, who looked abashed.

"Obviously they're both routinely exposed to danger, since their response was not fearful in either of our cases, and clearly Basil relies on David here completely, given his reaction when I released him," Sherlock finished.

"Precisely. Us," Basil agreed.

"Only mice," Sherlock said.

"I need toast," John said.

"I want cheese," David said at exactly the same moment.

"I don't suppose you're a consulting detective, too?" Basil asked Sherlock.

"Sherlock Holmes, at your service," Sherlock said, with an enormous grin.

"Basil Holmuis at yours," Basil replied.

John decided to retreat to the kitchen where he began putting on the kettle and making toast.

David shimmied up the table leg onto the kitchen table and looked it over. "I see yours is no better than mine is," he announced, surveying the general cacophony of objects with dismay.

John turned. "Just to be clear, you think this is as weird as I do, right? Mouse versions of me and Sherlock? Mouse versions that talk, no less?"

David looked thoughtful. "Probably not quite as weird. I would hardly think talking mice are surprising. But the rest of it…yes."

"Ah. Well, in that case, yes, Sherlock routinely leaves the flat in thorough shambles. He keeps the worst of it to his room, though, which is something," John shrugged.

David looked at him curiously. "Do you have any cheese?"

John peered into the fridge. "Just gouda."

"That's fine."

John shrugged and cut him a small piece, then he slathered jam on his toast and poured four cups of tea, which he put on a tray and brought out to Sherlock and Basil.

The two detectives were apparently mourning the destruction of Basil's violin and trying to devise a method for transferring music files from Basil's computer to Sherlock's. Apparently human-sized USB cables did not come with mouse-sized adapters.

Somehow, though John never did remember exactly how, the four of them ended up watching a Bond movie. David perched on top of Sherlock's head, of which Sherlock was oddly tolerant, whilst Basil watched from John's shoulder, periodically engaging in a volley of snark with Sherlock.

The next morning John woke in his own bed, cricket bat exactly where it had been the previous evening and was half-convinced he'd dreamed the entire thing until he went downstairs and found the spot where he'd cut out the little slice of gouda for his mouse counterpart.

He'd thought that would be the end of things with the mice, but Sherlock and Basil did manage to get the adapter problem worked out in short order, after cobbling together an adapter cable of their own. David introduced John to some of the movies in his collection, while Basil and Sherlock started swapping case notes and collaborating on experiments. A few modifications to various phones (which "magically" happened to John's even though he did not recall authorizing them), and the two detectives began feeding each other's texting addiction.

And if the two mice occasionally accompanied them to crime scenes, John couldn't argue with the handiness of their ability to fit into very tight spaces. And perhaps Sherlock and John sometimes let the two mice ride in their pockets in order to get them into buildings they otherwise would've had difficulty entering. Certainly the two of them running interference with the workers in an office building while Basil, David, and Detective Inspector Manfried worked a crime scene under one of the desks (complete with mini-forensic coveralls that Basil refused to wear) would go down in John's list of Highlights From My Life.

Sherlock never brought another cat to their flat. When John married Mary, David moved to their house with his wife, Laura (who Basil had accidentally introduced to him as she was a pathologist working in Bart's, of all things). When, years later, Sherlock and Basil both disappeared after a fight with Moriarty and Rattigan (who thankfully did not discover one another as the detectives had), he and David helped each other grieve and watched John's old Bond DVDs. And when they came back three years after that it was only after spectacular rows at Baker Street and a long discussion with each other that David and John forgave their friends.

Mary died. Laura did not, but she and David both came when John moved back to Baker Street with Sherlock. It was Sherlock and Basil together who badgered John back to life after Mary's death, though it was David who convinced him to accompany Sherlock on cases again.

Somehow, amongst the five of them, for all John never did quite manage to think of an entire society of talking animals as ordinary, they did manage to carve out a semblance of what passed for normal with Sherlock (or Basil) around. When John looked back, years later, his biggest regret was not being able to tell everyone the truth about some of their best cases. He and David both agreed to mask each other's involvement in the blog entries they wrote. But it would've made some incredible stories even better, if they could've told the truth about things.

Author'sNotes: Holmuis is Basil's last name in the Dutch version of the Disney film. I couldn't pass that up.

David's love of cheese is not just a mouse affectation, but comes from the books.