This is utter fluff crack. I mean it. Inspired by the bat!John AU so credit goes to the original creator there though this is a dumb, alternate take since human John is very much still a character here and Sherlock is just lazy about names. My sister was drawing Sherlock with bats on his head and so I wrote this dumb little crossover. Enjoy.


"Stephen, you can't keep it."

Stephen pressed his lips together and spun around on the stool, raising his eyebrows and crossing his arms. "Can't keep what, Wong? I have no idea what you're talking about."

Wong's stony expression did not change. He also had his arms crossed, but the effect was much more concrete coming from him. "The spirit. You cannot keep it."

"No spirit here, just me, so moot point thank you for your concern," Stephen said, spinning back around. Wong stepped forward and caught his arm around Stephen's body, his hand clapping down on his chest. Stephen recoiled and made a sound of disappointment, clasping at Wong's hand.

"You'll crush him, Wong!" he exclaimed, sliding off the stool and out of Wong's grasp. He had both hands cupped over his chest, like he was protecting his heart.

Wong raised an eyebrow and held his hand out, beckoning. "Give it here."

"He," Stephen said petulantly, pulling his robe aside with care and peering inside. "Not it. And he doesn't want to see you you nearly crushed him."

Wong gave an exasperated sigh. "You can't crush it-" Stephen glared at him and Wong rolled his eyes. "Fine, him you cannot crush him because he is a spirit."

"He's corporeal!" Stephen defended.

"Because he chooses to be," Wong said flatly. "It's optional for him. He's a protective spirit that enjoys corporeal form."

"I don't see why I can't keep him then. Protective spirit in my line of work, doesn't seem like a bad thing."

"You already have an over protective relic and an entire sanctum, and with the way you're behaving you're more likely to get injured trying to protect him than he is to actually help you."

"You don't know that!" Stephen said indignantly, planting his hands on his hips. The creature in his robe stretched one finely boned limb out and yawned, showing sharp little teeth. Stephen gave a little snort of surprise as the spirit began to crawl up his chest, the hooks in his limbs snagging on fabric until two pointed ears and white head showed just by Stephen's collar.

"Stephen," Wong said, and the spirit turned his head around to look at him with his beady black eyes. "You cannot adopt every magical thing that takes a liking to you."

"You're telling me I can't keep the magical bat spirit?"

"Yes, Stephen, that's exactly what I'm saying."

"You're not the sorcerer supreme."

"Neither are you."

"Not the point."

Wong narrowed his eyes at him. "Let the spirit free, Stephen."

Stephen crossed his arms and huffed. "He needs me. He was shivering, barely able to move in his old dimension. I'm not abandoning him back there. He's been in my tunic ever since trying to warm up."

"No," Wong corrected. "He's been in your tunic because that is the spot nearest your life-force."

"You're just angry that he picked me and not you."

"Your heart, Stephen," Wong said, sounding exasperated. "He was nestled against your heart. It's the natural inclination of a protective spirit to bond with the life force of its host, and in a human the greatest channel lies inside of the heart. They're parasitic, in nature."

Stephen snorted. "Parasitic, please. He was taking a minuscule amount of warmth and if he he's fond of my heart beating then we have that in common. I prefer it when my heart beats too. Contrary to your assumptions, Wong, I read up on protective spirits and I know that they aren't parasitic, for one. They are symbiotic. He isn't hurting me, I'm not hurting him. We're good for each other actually."

"And what will you do when your new pet dies defending you?" Wong challenged.

Stephen opened his mouth and then closed it, turning away and shuffling books around. "Not going to happen."

Wong gave a heavy sigh. "Stephen, it is in the nature of a protective spirit to bond deeply with a host and then defend it until the death. The death of the spirit, mind you, since without the host the spirit has no meaning and no purpose. The next time you are facing death the spirit will intervene."

"I don't see what you're complaining about then," Stephen said bitterly, stacking books and glancing over his shoulder. The bat was slowly crawling over the back of his neck, hook after hook in his tunic making soft scratching noises.

"Stephen," Wong said more gently. "You need to release it."

"He," Stephen said testily, gently taking the bat from his shoulder and stroking the soft, white fur. "Needs a host. You said it yourself. I'm sorry he picked me, Wong, but without a host now he's going to be lost. He'll fade and die. I can't reject him and I'm not taking him back to his dimension."

"You cannot just keep a being from another dimension like a pet!"

"He. Is. Not. Going. Back. Wong."

Wong and Stephen stared each other down for a moment, and the bat hung one wing off Stephen's hand before shuffling around, bumping his nose gently against Stephen's fingers. He climbed his way up between Stephen's thumb and first finger, pausing on the scarred back of his hand. Stephen glanced down when he felt something warm and wet, his eyes widening when he realized the bat was licking his scars. The intermittent tremors and the dull ache calmed.

Wong looked on with sympathy.

"Stephen," he sighed, placing a gentle hand on Stephen's forearm so the other sorcerer would look at him. "Maybe he doesn't have to go back. Give him to someone else to bond with, before he's too attached to you. Our line of work is too dangerous for a spirit as small as this. He will be killed within the year. He needs another host."

Stephen felt an odd lump in his throat and he sighed, gently removing the bat from his hand and cradling it again near his chest. "Yeah, alright." He said finally, brushing away a tear as the ache slowly came back to his hand. "I think I know someone."

Sherlock wasn't home when Stephen appeared in his flat, so Stephen waited. It was past midnight when the detective arrived home, pausing in his doorway as he slowly removed his scarf, his icy eyes looking the sorcerer up and down.

"Don't tell me you need my assistance with another demon?" Sherlock said at present. "I refuse to believe this is a social call."

"Not yet, no," Stephen admitted, rising from where he'd been sitting in Sherlock's arm chair. "I did bring more of that tea you liked so much though."

Sherlock glanced in the kitchen for a moment before flicking his gaze back to Stephen and narrowing his eyes. "What do you want?" Stephen hid his smile. Sherlock wasn't showing it, but he knew how much the detective coveted that tea.

"I'm actually here to give you something. A, token, you could call him."

"Him." Sherlock glanced around but his suspicious expression didn't change. "Another of your supernatural friends, perhaps?"

"He's not supernatural, just from a dimension we don't interact with much," Stephen said, gently removing the bat from inside his tunic. He held up his outstretched finger. The bat was hanging from it and gave a sharp-toothed little yawn, stretching both wings before folding them back up and swiveling his head around to look at Sherlock.

"You've brought a bat into my flat."

"He just looks like a bat. He's a protective spirit. A mild one, and he bonded to me. Unfortunately I can't keep him or put him back in his dimension, and without a host he'll die. I figured, your line of work you could use something like this. And I was hoping our...similarities would ease the transition."

"You want me to babysit a spirit that's taken the form of a bat?" Sherlock said, pouring some of the tea and crossing one arm over his chest as he leaned his lower back against the counter. "You must be joking."

"He could be good for you. I know you're dying of curiosity, he's from another dimension imagine what you could learn."

Sherlock rolled his eyes, but he sighed and pushed off the counter. "Fine, let's have a look." He bent and squinted at the bat, teacup still firmly in hand. The bat turned and looked at him back. They stared at each other for so long that the bat finally reached out a wing and papped Sherlock's forehead with it. Sherlock blinked and straightened up, but gave no other reaction.

"I don't think it likes me."

"He likes you just fine, you just have to give him time. He gets cold easily so keep him in your coat, near your chest. Protective spirits are drawn to life energy and in a human that's your heart."

Sherlock pressed his lips together, but he hadn't said no and he was still looking at the bat. "What does he eat?"

"Energy. It's a symbiotic relationship. He helps you, you're something warm and alive for him to feed harmlessly on. You won't even notice the energy he takes, it's so insignificant. Promise."

Sherlock reached a hand out slowly and touched the bat's ear. The ear flicked around and the bat reached out both wings, hooking onto Sherlock's finger. Sherlock went to pull away but the bat came with him. Clinging to his hand.

"There, see?" Stephen said brightly. "He likes you."

The detective held the spirit up at eye level, skepticism barely hiding his curiosity. "Fine, but if he proves a nuisance I'm bringing him back to your sanctum."

Later that morning, when John got off work he was greeted by the sight of his flatmate laying on their couch with his fingers characteristically steepled and a small bundle of white fur laying on his chest.

"Sherlock," he said slowly, setting his coat aside. "Why is there a bat on your chest? Are you even aware of it?"

"Him," Sherlock said lazily. "And yes. John, meet John. He's supposedly a protective spirit your mystical doctor friend wanted me to play host to."

John blinked. "Mystical—Strange? Doctor Strange was here? And he left you a...bat. That you named after me."

"He's small, wears white and seems abnormally attached to my heartbeat. Felt appropriate and I didn't feel like sparing creativity on names."

"Right, need all that for the experiments you're going to do on the poor wretch," John said, sighing and crouching down so he could look at the bat that had stolen his name. The bat's eyes were half closed but his ears pricked up and he turned to look at John.

"I cannot believe you have an inter-dimensional pet," John said at last, straightening up.

"Spirit," Sherlock corrected.

"Spirit, right, of course. What exactly do you intend to do with this bat spirit you've replaced me with."

"Don't know yet."

John massaged his forehead. "Right. Well. I'm going to bed."

Sherlock didn't reply, and John shook his head at the sight of the two on the couch.

Months later, when John had moved out with Mary and was just starting to get used to not having Sherlock over his shoulder every five seconds, a small white bat came darting through the cracked window and lit on John's chest. John startled and froze in bewilderment for all of three seconds before realizing what the omen meant. Even before John had moved out the bat had identified him as the most capable when Sherlock was in trouble, and they'd learned quickly how to communicate. Even though he kept threatening Sherlock had never once done experiments on the spirit and John quickly figured out that he never intended to. Sherlock actually seemed fond of the little thing.

"Right, John," he said to the bat, shrugging his coat back on and grabbing his first aid bag. "What has he gotten himself into now?"