Disclaimer: I don't own any of the iterations of Sherlock Holmes that exist in the world, but in particular no the BBC's Sherlock, nor do I own Buffy the Vampire Slayer.
Buffy came to in a warehouse. Because of course it was in a warehouse. She was also in a heavy iron cage with a faint hum of magic in the air from wards set up around the building, and spells strengthening the bars around her. A door on the far side of the room was cracked open, and a moment of careful listening told her that there didn't appear to be guards outside. Quentin Travers was talking to a flunky in the shadows on the other side of the room, softly giving instructions on what to tell the government offices; she presumed in his efforts to get the Watcher's money back into his hands. A slight flexing of her muscles told Buffy that she'd been injected with that damned Cruciamentum drug, so even if she broke free, she'd be weaker, less flexible, less resistant and have much more limited stamina.
In a cage next to her was Mycroft Holmes who looked remarkably worse for wear.
"Ms Summers," he said. "You . . ." he paused, then began again. "Mr. Travers has implied that he was able to . . . to brainwash," his distaste for the word evident in the way he said it, "me into acting in favour of his interests, and indeed to ignore his current physical state. I don't suppose there is a chance you can explain this?"
Buffy shot him a wry look. "I have a few guesses, but I honestly don't know how much you do know, so sorry if I go over something unnecessarily."
"I suspect that, as regards this situation there is a great deal I do not know," Mycroft replied dryly.
Buffy sighed. "Well, to start, how aware are you of the supernatural? Putting aside idiots with too much time on their hands wittering about menstrual power blood forces." Then she paused. "Wittering? God, Sherlock, this is your fault."
"I was wholly unaware of any genuinely verifiable paranormal persons or activities until Mr. Travers enforced his will upon my person today," he said.
She grimaced. "Okay, I'm not going to go into too much detail, just because this really isn't the time for lengthy history lessons. The short version is that millions of years ago the earth existed, metaphysically speaking, much closer to what we call 'hell dimensions'. That is, places full of monsters that like to kill humans for fun and food and think of humans as a plague. At some point the earth pulled away from those dimensions leaving some traces behind, like magic and lesser demons. There's a lot more stuff, but the part that's pertinent to us is the Slayer and the old Watcher's Council."
Sherlock's brother blinked as she paused, taking in the information and putting it together the way his brother would have. "Mr. Travers is part of this prior Watcher's Council," he said. "I assume the explosion that destroyed their central offices in London was the reason for your reconstituting the council elsewhere, and that there was a pre-existing disagreement between yourself and Travers regarding the policies of the organisation." He then tilted his head slightly, remarkably like Sherlock in that moment and said, "You are apparently this Slayer that he mentioned. You . . . hunt the so-called 'demons'?" he inquired.
Buffy nodded. "In short, I act as a supernatural enforcer, and I kill those things that can't seem to coexist peacefully with humans."
She had to give it to him, Mycroft was as quick as his brother. "I would assume the council has been taking advantage of these Slayers over the centuries, given your statement about not being paid prior to your revised policies."
"If you want to listen to the chit, you could see it that way," Travers interrupted, having made his way over from his shadowy corner. "I would see it more as the sword in my hand claiming it deserved payment for being wielded."
Letting out a hiss of annoyance, Buffy said, "And that's why I don't like you, Travers. You're exactly the kind of person who thinks a maid should be so grateful to mop up after you that she shouldn't be paid to do the work."
"No," Travers sneered. "I think that a non-human thing like a Slayer should be grateful for the chance to assist her betters."
Mycroft was desert-dry as he said, "Your definition of 'betters' seems distinctly different from my own."
"Please," Travers spoke with a ghoulish and sarcastic smile, "Do keep speaking of that which you know nothing." He gestured to his flunky, who came and unlocked Buffy's cage. She had a fairly good idea this was going to be bad, and that she wouldn't be able to get away. For all that she was well-trained and used to fighting opponents stronger than herself, Buffy knew she was also unused to the limits the drug placed on her. She subtly palmed the lockpicks she carried on her in case of emergency and flung herself out of the cage to take the flunky and Travers by surprise.
The fight was quick, brutal, and she lost.
As she was dragged off, she struggled and shouted, making a spectacle of herself to distract everyone from Mycroft snatching up the lockpicks. Hopefully he'd learned how to use them and would be able to escape. Even though she was sure Sherlock, John and Francesca would find her, she couldn't just leave his brother to Travers' tender mercies, and if he got away it would probably speed up the rescue attempt.
"Pathetic," Travers said. "A true slayer would have escaped."
"Do you have records confirming that?" Buffy asked, curious. "Because using a couple glamoured demons to pile onto someone with only average strength and everything seems a little much."
Travers gestured in lieu of answering and the thug punched her in the stomach. Not long after that she was too busy trying not to scream to think about anything else.
A few phone calls by Francesca had produced several of Anne's friends, willing and able to storm whatever location she was at, as well as Dawn and Illyria. Anne's sister and her unusual paramour had accompanied him to Mycroft's office to allow him the opportunity of further investigation. He found nothing particularly illuminating, though it seemed it had been arranged for the whole staff to be replaced by workers from various office pools and tertiary staff meant to take on various roles should the normal primary and secondary personnel be unavailable.
They were already gone, the demons replaced with faces Sherlock well knew. Worse, with their usual efficiency the staff had cleaned and cleared and removed any hint of clues that might have determined what happened to Anne (and Mycroft, but he didn't care about Mycroft. He didn't. Didn't, didn't, didn't).
Sherlock's mobile beeped to indicate an incoming text.
Mycroft is here. He says Buffy helped him escape from someone called Quentin Travers.
"We have to return to Baker Street," Sherlock told the pair. "John says Mycroft has appeared and is claiming to have escaped from a Quentin Travers."
"What!?" Dawn was shocked. "Travers? But he's dead. We checked and he was in the Watcher HQ when the First had it blown up!"
Only a moment of thought and many pieces slotted into place about events Anne had not spoken of directly, ongoing concerns she had regarding the other slayers in their organisation that had seemed overwrought, but now had a definite base in previous experience, and not least some rather dark statements about missing records and contacts.
"Then we shall have to inquire of Mycroft what precisely came to pass," Sherlock said, spinning around with calculated flair.
When they arrived back at the flat, Mycroft was sitting in John's chair, pale and discomposed, while the doctor took his pulse. The brief flash of light in John's other hand told Sherlock that John was using his magic to probe more deeply. "Sherlock," Mycroft said, then stopped. He closed his eyes and inhaled deeply as though seeking an inner calm.
The animosity that had arisen between them those several years back when Mycroft had begun lording his greater knowledge over his younger brother, pushing and pushing for greater control over his every movement and the constant snide comments about emotional investment boiled over briefly. His brother was now fine and every second he delayed doubtless meant ill for Anne. "What information do you have?" Sherlock snapped. He looked his brother up and down. "And I would appreciate if you did not play games."
Mycroft seemed to shake himself, then said, "Travers had us captive in a warehouse." He said the address, then added, "If he has not taken Ms Summers elsewhere, I would be surprised."
Nonetheless they all went, John and Francesca carrying their magical supplies in case such was required. At the warehouse Travers had indeed moved them elsewhere, and Sherlock hastily searched the place, texting Mycroft as he went in the hopes of finding something useful in the CCTV footage. The dirt tracks on the floor from someone's boots indicated a location near Cirencester based on the colour and composition of the dirt, but that was only a place one person had been in recently, not an indicator of a definite location.
They were forced to return to Baker Street where Sherlock set himself to pulling from Mycroft every bit of information his brother had observed. He was about to turn back to his work when Mycroft spoke. "I owe you an apology, Sherlock."
Mycroft had apologised for nothing as far back as Sherlock could recall. He was just as prideful as the detective, and had usually preferred to intimate apologies through actions such as replacing damaged items or providing Sherlock with information without requiring a bargain. Once he had determined that he needed to control every action his younger brother took with a supercilious smugness and personal invasiveness of such appalling degree, Sherlock had dismissed ever getting an apology. Mycroft had clearly deemed himself so far above his younger brother as to treat him like the goldfish he accused the average person of being.
With that in mind, he responded the only way he could. "Whatever you want from me, Mycroft, it will wait until I have Anne safely back."
His brother openly winced. "I deserve that. As soon as this is resolved I will remove the ongoing surveillance on you as well as the conditions on your part of the family trust."
"Why now?" Sherlock asked. It was an unnecessary delay, was ridiculous and . . . "Why?"
"Quentin Travers used a . . . spell . . . on me," Mycroft's distaste for the wholly irrational concept was clear. "It was to allow him the ability to control my actions - my thoughts, even." He looked up at Sherlock, an intensity apparent in every line of him. "On a day-to-day basis I was not aware of these controls, the orders I was under. But upon consideration of my actions in this light, I have become aware that I was acting in ways that were not my conscious choice."
Sherlock eyed him. "Which affected your policy, your work and your employees-"
"He was trying to protect you," John told him.
For a moment, he felt his mind spin, twirling this information around, examining John's assessment from every angle to see how it applied to what Mycroft was saying.
"He wanted you as far away as possible from the spell that was causing him to act against his interests or governmental interests. So he acted specifically to drive you away."
"Subconsciously," Mycroft clarified. "I do not want you harmed, Sherlock, but while in that state I was not consciously cognisant that I was acting out of character, on some level I worried I would be driven to act to your detriment. By keeping you away it meant you were less likely to be harmed by whatever demands might be placed on me."
Long ago, the brothers had a facial language all their own. Something to allow them more entertaining conversations in mixed company than could normally occur, especially as Mycroft had always desperately wanted his dignity to be unassailable, and Sherlock enjoyed working around people.
You really mean it? A tilt of the head, patterned blinking, a flaring of nostrils.
Yes. The subtlest of nods. I only ever wanted you safe and well.
You'll stop interfering?
Within reason.
Mycroft had always been an interfering so-and-so, but to no longer have to waste time on finding all the hidden cameras in his home, to no longer have every single person he chose to spend time with investigated and then intimidated, to no longer worry his brother would show up just to talk at him, it would be a relief.
I'll stop stealing all your biros. Sherlock shot his brother a small smile with that sally.
I genuinely can't stop mummy from harassing you.
Sherlock made a face and turned back to his work. "Mycroft, did you access any CCTV footage that would be useful right now?"
They bent to their work.
As they drove out to the Cotswolds property that Sherlock had determined was where Buffy was being held, John watched Sherlock carefully out of the corner of his eye. The discovery that Mycroft and Sherlock's relationship had been much closer some years before and that the elder brother's incessant invasiveness was a side-effect of a spell made the underlying tension between the two much easier to understand.
Sherlock was settled into his seat in the car, clearly buried deep inside his mind palace, the occasional slight twitches of his fingers indicating the detective was moving things about inside. John used his usual tactic of slipping a bottle of water into Sherlock's hand at just the right moment, causing him to take a drink without realising he'd done so.
The look from Dawn at the pair of them made John sigh. "Please don't start telling me that I'm in a romantic relationship with him. I really don't want to deal with Buffy if she misunderstands you insisting on it to mean that Sherlock is stepping out on her."
"Wait . . . she's going out with him?" Dawn's jaw dropped. "But he's . . . smart! Buffy's never gone for the really smart guys!"
"She told me once that her . . . her boyfriend Angel spoke at least five languages with some fluency as well as handling several offshore bank accounts for various ill-gotten gains as a vampire. Riley was a TA at university, suggesting he was a post-graduate student at the time, or at least had the capabilities." John spoke with deliberate mildness. He well knew Buffy's ongoing tendency to pretend she was little more than a fashion-obsessed Californian party girl and that she didn't always quite factor that into her hurt feelings.
Dawn opened her mouth, appearing about to object to the implications and then winced.
"I appreciate your intervention, John," Sherlock commented. "I suspect Anne would little appreciate such things from myself."
"Not a problem," John told him, then at the appropriate moment of distraction slipped the detective one of the little tiny scones he and Mrs. Hudson used to sneak around Sherlock's refusal to eat during cases.
When they arrived the whole thing started as a rational and calm operation which turned into a mad firefight and minor pitched battle when Dawn spotted Buffy, bruised and bleeding, slumped on the floor of an iron cage. The younger Summers flung herself through the door, followed by Illyria who stormed through like the force of nature she was, forcing the other backup to follow in a disorganised mess that made John's inner professional soldier wince.
He set up with his gun in front of the cage while Francesca and Sherlock got into it, pulled Buffy out and got her to the car park. John followed the pair out as they carried Buffy, guarding the rear until they were safely outside and settled into the back of a van. John switched from a soldier's consideration to a doctor's, passing Sherlock the gun. "Keep an eye out, would you?"
"Hey. Mycroft make it to you or do we have to stage a rescue for him, too?" Buffy asked weakly.
"I cannot believe you would sacrifice your health and welfare for Mycroft," Sherlock said with great asperity.
John ignored them both and gently began palpating Buffy's abdomen. "Can you have the argument later?" he asked.
"It's just cracked ribs," Buffy informed him. "I mean, okay, the Cruciamentum drug, whatever it's called, it'll delay my healing, but once that wears off I'll be fine."
"You need stitches, and it's clear these will have to be wrapped, if only to remind you not to overextend," John said. He was already cleaning and bandaging the things that required that minimal care. "You have a concussion - that much is obvious from your pupils- and you'll be coming back to 221 and no arguments."
Sherlock spoke from his position guarding the door. "John's kit is in the flat, it would be illogical to take you to yours where he would have fewer resources available for his use and is less accustomed to working."
"Love you too, Sherlock," she said.
The fighters soon spilled back out of the building, Illyria looking self-satisfied in a way that suggested she had gone on something of a rampage. "Buffy, are you okay?" Dawn demanded.
"I'm fine, Dawnie," said the Slayer, trying to shift herself to look as though she wasn't sagged against the door.
"Stop that," John said. "You said they gave you some sort of drug that's reducing your normal healing factor and I expect you not to aggravate your injuries until that wears off."
Dawn's eyes were wide and horrified. "The Cruciamentum drug? I'm calling Giles."
"Don't call Giles," Buffy said.
Sherlock spoke up, "Dr. Giles should absolutely be contacted as I assume he would have better access to the composition of the drug, which would confirm whether there are any ongoing difficulties that should be expected in your recovery." Now that he no longer needed to guard the van, he handed John the gun and settled next to Buffy, arranging himself around her in a way that allowed her to sit up better, but simultaneously not strain her injuries.
"Stop being so accommodating and perfect," Buffy grumbled. "I'm trying to be mad at you."
Instead of listening to her, John was amused to see Sherlock begin talking Buffy through some of his deductions about the people present, while Buffy corrected him with her own observations or made scoffing sounds about how entirely obvious it was that Paul the Anamovic demon worked as a plumber from the wear on his boots and jeans and did he really think she was that oblivious?