"I'm not going to lie," John Watson followed his friend into the kitchen. "I have ulterior motives for staying here so late."

"Ulterior motives?" Sherlock filled the kettle and placed it on the stove.

"Yes, Mrs. Hudson asked me to. Apparently, she's worried about you." Facing the doctor with arms folded across his chest, he scoffed.

"Mrs. Hudson worries when I get the sniffles. What's she on about now?"

"Says she wakes up in the middle of the night to hear you carrying on."

"Carrying on?"

"Yeah… you know, talking and laughing…. she says you seem to be having entire conversations by yourself."

"Thats ludicrous. I wasn't talking to myself."

"I know, I told her how you use to talk to me when I wasn't….."

"I've company come for tea."

"What?" The response was a hum as the host turned on his heels at the sound of the kettle and began pouring tea.

"Ah! Here he is now!" An obviously excited Sherlock clapped his hands before offering one to a small brown rodent John hadn't noticed scuttle across the counter. "John, I'd like you to meet Basil. He's been coming round for tea."

"Thats a mouse."

"Yes."

"You've been talking to a mouse in the middle of the night."

"Well, we don't just talk….. Its tea…. so we also drink tea and eat biscuits." With his free hand, he prepared Basil's setting as he had the nights before.

"You've been having tea and biscuits with a mouse."

"Yes. I've been having tea and biscuits with a mouse and you are being very rude to him, frankly."

"Me? I'm being rude?"

"Yes, I've conditioned him to expect a handshake upon meeting new people and you haven't even acknowledged him." John squinted his eyes at his friend a bit and looked down at the little creature in his hand, standing on its back legs, its paws were actually a bit out stretched. Returning his attentions to his friend, he saw a subdued eagerness and excitement. Sherlock was hopeful and expectant of John and the doctor decided the best course of action would be to play along and see where this might go.

"Ok." Turning back towards the mouse, he paused. "How have you taught him to shake hands?"

"Just offer your finger."

"My finger?"Another sigh as he stretched his index finger out to the small creature his bizarre friend was oddly attached to."Alright, nice to meet you, Basil. I'm, ah, John."

"Oh, he knows who you are." Sherlock informed him.

"He does, does he?"

"Uh-huh, told him all about you."

"Right. Well, I've heard nothing about you, Basil." John forced a friendly enough smile towards him as Sherlock set him on the table and he climbed onto his saucer. "Right."

"Well, theres not much to really know about Basil. He's a very affectionate flatmate."

"What—?" "Experiment." Clearly uncomfortable, the shorter man adjusted and lifted his own mug to his lips, mostly to keep it off the table and away from the mouse he was trying to understand. Sherlock looked very much like a kid with a new toy at show-and-tell.

"So, uh— yes,… you have….. you have been talking to a mouse?"

"Well he's more interactive than my skull and he's not quite as argumentative as you."

"Because you wouldn't want others opinions to disrupt your thought process." John returned the questioning stare he received by chuckling and taking another drink from his mug.

"You know he's quite clever." The man-child broke the silence.

"I'm certain he is."

"No, I mean, it." Quickly, he dug out his mobile, opened the key board app, set it down. Basil, in response, appeared to clean himself before climbing on. Once again banging out a tune that only meant anything to him.

"And whats that?"

"He plays when he's thinking."

"Like you and your violin?'

"- my violin. - Exactly."

"Well— what—ah, what is he thinking about?" The doctor wondered if maybe an answer would give him a glimpse into his friends seemingly worrisome behavior.

"No idea…. mouse… things."

"Of course…. what kind of problems could a mouse have?" The Nonsense Movement being composed on the table stopped and the creature approached Sherlock, looking up expectantly.

"John, look, now you've upset him." The dark lanky detective picked up the mouse and it crawled onto his shoulder where it was offered more biscuit and a pet.

"That matters why?"

"Well, I'm attempting to socialize him and it won't work out if every interaction is as negative as this one." The two stared at each other a long while. "Apologize."

"I—what?!"

"Apologize. Isn't that what you would have me do if I upset someone? Make me apologize?"

"Yes, but—"

"Well." He offered his shoulder to John who sighed and cleared his throat.

"I'm sorry, Basil." Cautiously, he ran a finger along its furry back.

"He doesn't like that." Quickly, he withdrew it.

"Ok."

"Only me."

"Ok, Sherlock." Another awkward silence.

"He can count to two."

"Oh, really. Thats—ah—that's brilliant." Excitedly, Sherlock set up a small demonstration, using bits of biscuit and, while John was certain the mouse was enjoying a nice snack, the other insisted he genuinely could count to two, and appeared a bit offended at the suggestion it was anything different.

"He's just eating biscuit crumbs."

"No, he's only eating two biscuit crumbs."

"He just picked up the two biggest ones."

"But, he had five options and he's done this before. Its not an isolated incident." John grabbed the bridge of his nose. "What makes you so reluctant to believe he can count?"

"Because he's a mouse."

"So, mice can learn."

"Yes, mouse things."

"Counting can be a mouse thing."

"Why are you so convinced he can count?"

"Because he is counting. I taught him." After a moment of exchanging exasperated looks, he continued. "Look, you didn't know how to count until someone taught you. Basil is the same. They don't have little mouse schools or the like, I don't believe."

"So you figured you'd open one up in your kitchen. Well done." John lifted his mug and raised his eyebrows as he took another drink.

"Why exactly do you have a problem with Basil?"

"You're joking, right?" Fighting the laugh was hard, a chortle escaped.

"No, I'm not. What could you possibly have against him. You just met him."

"I don't know, the plague."

"Right, well, if you're going to insist on being rude to my friend—"

"Friend?" "Experiment." The correction was quick. "I'm going to have to ask you to leave."

"What, me? You're asking me to leave."

"Thats right."

"And you're serious."

"Yes." John couldn't contain his laughter this time, though he was also concerned for his friends sanity, the situation was beyond absurd to him. "Basil has been nothing but accommodating and you, I'm afraid, are the one causing the problem."

"Right, ok." John finished his tea and grabbed his jacket. "I hope you and your experiment have a very productive tea." Once John was gone, Sherlock turned to his new companion.

"Sorry about that. Very out of character for him. Not sure why he was acting like that."

Squeak.

"Well, I'm glad you thought so because I'm certain he'll come around." Even Basil could see the worry in his eyes, despite his smile.

—-

John climbed into bed with his fiancée and Mary leaned over, planting a kiss on his forehead before curling onto his chest.

"I figured you'd be a lot later or I would've waited up for you."

"He's talking to a mouse."

"What?"

"Sherlock Holmes is talking to a mouse. They have tea together. He laughs, lets it waddle all over the musical keyboard on his mobile, and is completely convinced he taught it to count."

She thought for a moment.

"Well, I'll definitely be thinking twice about ever touching his phone again." The two shared a laugh. "You're worried about him."

"Of course I am. He called a mouse his new flatmate, his friend and his experiment while we were talking."

"That's cute."

"Cute?"

"Yes, he has a pet." John laughed alone this time.

"I don't know if Sherlock has ever had a pet or even understands why anyone would want one."

"Maybe that's why he doesn't know what to call it." Her partner contemplated this for moment before agreeing and attempting to go to sleep, but try as he might, he couldn't get The Nonsense Movement, as he jokingly decided to call it, out of his head.