There was something a bit spooky about Sherlock Holmes. John Watson noticed it the first time they met. It wasn't just his pale skin and otherworldly beauty. It wasn't just the way he knew things about John without being told. It wasn't even that he mentioned having left his riding crop in the morgue. No, there was something more…

John was intrigued. Intrigued enough to consider moving in with him. Intrigued enough to overlook the human skull on the mantlepiece and the body parts in the fridge. Intrigued enough to follow him to a crime scene, only to be abandoned there.

Limping away from said crime scene, John glanced up at a nearby rooftop. His mouth dropped open at what he saw: Sherlock, silhouetted against the rising full moon. Realising that he was gawping like a fool, John looked around to make sure he wasn't being observed. When he turned back, Sherlock had vanished. All that remained on the rooftop was a small black kitten, padding between the chimney pots.

A month later, John could barely remember what his life had been like before Sherlock. His limp was gone, along with his feelings of hopelessness and boredom. Life with Sherlock wasn't easy, but it was certainly never dull.

Between clients, cases, and seemingly random experiments, John never knew what he'd find in their flat. He'd grown accustomed to all manner of bizarre, noxious, and at times horrifying intrusions into his living space. One evening, however, he discovered an intruder of a distinctly un-horrifying variety.

John had returned to the flat much earlier in the evening than he'd planned, having been stood up on a blind date. He called out for Sherlock, but was unsurprised to receive no answer. He was surprised, however, to see a little black kitten peeking it's head out of Sherlock's bedroom.

"How'd you get in here?" John asked.

The kitten, of course, didn't answer. It just blinked its odd aquamarine eyes at him.

John moved slowly toward the kitten, but it turned tail and disappeared into Sherlock's bedroom. When John followed, he found an open window, and no sign of the kitten.

A month after that, John spotted the kitten again. Or, he amended in his mind, another little black kitten with aquamarine eyes. It looked exactly like the first one, but it couldn't be the same, since that one would have grown a bit in the intervening weeks.

This time, the kitten was curled up in John's armchair when he arrived home after being mercifully released early from what he had expected to be a double shift at the clinic. The kitten blinked slowly up at him and yawned, evidently having just awakened. John couldn't help smiling.

"Well, hello there, little one. Am I interrupting your nap?"

The kitten stood and stretched. Its legs were surprisingly long for such a small body. It looked painfully thin, but otherwise healthy.

"Let's see if I can find something for you to eat," John said, moving into the kitchen.

He rummaged around in the cupboards until he came up with a tin of tuna. He opened it and placed a small portion on a saucer that seemed to be uncontaminated by any of Sherlock's experiments.

"Here, kitty kitty," John called.

He expected the strong scent of fish to bring the kitten running, but it did not appear in the kitchen. He looked in the sitting room. No kitten. He searched the flat. No kitten.

With a shrug, John made himself a tuna salad.

Several weeks went by with no kitten sightings. Then one evening, while Sherlock was out doing god only knew what, John went down to Mrs. Hudson's flat to borrow some milk, and found a small black kitten lying in front of her fire, paws tucked up under its chest.

"Who's your new friend?" he asked.

"Just a stray who wandered in and made himself at home."

The kitten blinked slowly up at them with aquamarine eyes.

"Have you seen a black kitten with eyes that colour around here before?" John asked.

"Oh, there are so many feral cats in the neighbourhood, I can't keep track," Mrs. Hudson said.

John peered more closely at the kitten. It looked identical to the two he'd seen in 221B — the same age, the same glossy black fur, the same hauntingly beautiful eyes, the same too-thin little body.

"He's a dear wee thing," Mrs. Hudson said. "I think I'll let him stay."

"What're you going to name him?"

"I'm not sure. With those eyes, maybe I'll call him Sherlock."

The kitten began to purr.

When Sherlock returned to the flat the next day, John was amused at the prospect of introducing him to his new feline namesake.

"You'll never guess what Mrs. Hudson's done," he said with a grin.

"I never guess," Sherlock said haughtily. "I deduce."

"Yeah, well, you'll never deduce this!" John challenged, dragging Sherlock down the stairs.

Before he could tap on her door, Mrs. Hudson opened it.

"Oh, John, dear, have you seen Sherlock?"

"He doesn't have eyes in the back of his head, but I'm fairly certain that he saw me as we were descending the stairs together," Sherlock said from behind John.

"Oh, not you, dear. My kitten."

"You have a kitten named Sherlock?"

"Told you you'd never deduce it," John laughed.

"I have, in fact, deduced it completely. Mrs. Hudson allowed a stray cat to wander in off the street, decided to keep the ridiculous creature, named it after me based on a superficial resemblance, left a window ajar last night for a bit of fresh air, and woke to find that her new pet had returned to the street where he belongs."

"Oh, Sherlock, he doesn't belong on the street! He's just a wee mite of a thing. He'll be set upon by dogs, or run down by a careless motorist. I have to find him!"

"I wouldn't worry," said Sherlock. "Cats are independent by nature, and quite capable of taking care of themselves."

"I'm sure he'll turn up," John said.

The kitten did not turn up. After several days of fruitless searching, Mrs. Hudson allowed John to persuade her that he must have been someone's lost pet, and was now reunited with his rightful owners.

A few kitten-free months passed by.

John didn't miss his feline visitors, as his flatmate was catlike enough to remind him how much trouble a kitten could be. Sherlock came and went at all hours as he pleased, periodically disappearing overnight without any regard for whether or not John might worry about him. He was by turns aloof and demanding, giving John the cold shoulder one moment, and invading his personal space the next. He was finicky about what he ate, and meticulous in his personal grooming. He often kept John up at night with the caterwauling of his violin.

And John, heaven help him, was gradually falling under Sherlock's spell.

One stormy night, when Sherlock had once again buggered off without so much as leaving a note, John returned from the pub to find a rather bedraggled kitten in the sitting room, licking rainwater from its glossy black fur. The kitten blinked slowly up at him with aquamarine eyes before resuming its grooming.

John felt the hairs rise on the back of his neck.

Something strange was going on. This kitten looked just like the two he'd seen here before, and the one in Mrs. Hudson's flat. But that had been months ago. Those kittens would be nearly full-grown by now.

Was this a ghost kitten, haunting 221 Baker Street?

Absurd.

But still…

John very slowly made his way over to the sofa and sat down. The kitten, now relatively dry and fluffy, regarded him curiously. John leaned down and reached out a tentative hand.

"Are you real?" he asked.

The kitten gave John what he could only interpret as a scathing look. It rose, stretched, and stalked over to sniff at his fingers. John held perfectly still. He could feel the tickle of tiny whiskers and a faint puff of breath.

Evidently John's scent passed muster, because the kitten began to wind itself around his ankles, purring. John allowed his hand to trail down to stroke the small, warm body. The kitten arched up into his touch.

Not a ghost, then.

"Sherlock, are you running some sort of experiment with kittens?" John asked the next morning.

"Why would I be running an experiment with kittens? They hardly ever feature in crimes."

"Right. But I keep finding kittens in the flat."

"They're probably strays who climb the fire escape and come in through the window."

"Well, that could explain how they get in, but it doesn't explain why they're always black, with blue-green eyes."

"Must be the gene pool of the local feral cat population."

"And why are they always the same age, and the same size?"

"Perhaps that's the developmental period when they leave their mothers."

"I don't think so. They seem too young to be out on their own. And another thing — why do they only appear when you're not home?"

"Maybe there are no kittens, John. Maybe they're a figment of your imagination."

"Nope. Mrs. Hudson saw one, too, remember?"

"She was probably high on one of her herbal soothers."

"I'm going to tell her you said that."

"Please don't. I smell scones baking."

The next time a kitten (the kitten?) turned up, John was again alone in the flat. Well, alone except for the small black bundle of fluff with aquamarine eyes.

The kitten — if it was the same kitten, which of course was impossible — seemed to remember John. It came sauntering out of Sherlock's bedroom and hopped right into his lap, where it turned around three times before curling up and beginning to purr.

John began to track the kitten's visits. He soon noticed a pattern. The kitten only appeared when Sherlock was out. It only appeared at night. And it only appeared during the full moon.

John supposed he ought to have found this more alarming, but the truth was, he'd grown attached to the kitten.

For its part, the kitten seemed to have grown attached to John, as well. As the months went by, it became more and more affectionate, rubbing against him, nudging its head up under his chin, or flopping over onto its back to solicit a belly rub. While John read, or watched the telly, the kitten spent hours curled up on his lap, kneading his thigh with its little black paws, claws always kept carefully sheathed. Its steady purr never ceased.

In this way, a year went by. John made sure to be home by sunset whenever there was a full moon, and Sherlock, for his part, was always unaccountably absent on those nights. After that first unsatisfactory attempt, John had never again mentioned the kitten's visits to Sherlock. He didn't want to have his sanity questioned, and he felt oddly protective of his relationship with the little kitten.

As for John's relationship with Sherlock, that was, if possible, even more complicated than his relationship with the kitten. John had long acknowledged to himself that his feelings for his flatmate went far beyond mere friendship. To acknowledge the same to Sherlock, however, seemed fraught with peril.

Sherlock's own feelings were a mystery to John. At times he could almost believe that Sherlock felt the same way about him that he felt about Sherlock, but without knowing for sure, John was afraid to risk what they had for the chance at something more.

One night, instead of disappearing out the window as it usually did when John went to bed, the kitten followed him upstairs. Its aquamarine eyes watched intently as he changed into his pyjamas and slid under the duvet. Then it leapt onto the bed and curled up on his chest. The soothing vibration of its purrs lulled John to sleep.

John drifted toward consciousness with the feeling of soft hair tickling his neck. Oh, right — the kitten had stayed with him. Keeping his eyes closed against the morning light, John brought his hand up to stroke its silky fur.

In the next instant, John jolted fully awake as his fingers tangled in Sherlock's curls.

"Sorry! Uh, um… I thought you were the kitten!"

Sherlock said nothing. He just lay there, blinking slowly back at John with his aquamarine eyes.

John stared. First at Sherlock's eyes, then at his own fingers, still wrapped in Sherlock's hair, then back at those strangely familiar eyes.

"Sherlock?" John said, barely more than a whisper.

"Hmmm?"

"Are you the kitten?"

"And if I were?"

"You'd, uh… You'd be welcome to sleep here, on a regular basis."

"By a regular basis, you mean every full moon?"

"If that's what you want," John said. Then he steeled himself. The time for pussyfooting around was over. "Or, if you prefer, it could be every night."

Over the beating of his heart, John heard a low, deep rumbling. It took him a moment to identify the sound. Sherlock was purring…

...

End Note: I have a couple other new spooky Johnlock stories for you - How Sherlock Got the Willies and Bad Cocks Rising. You might also enjoy these tales from last year - The Case of the Ghost with the One Black Eye, The Little Army Doctor Who Was Not Afraid of Anything, Going on a Hound Hunt, and In the Dark, Dark City.

Happy Halloween!