Disclaimer: I do not own these characters, and am making no profit from their use (this applies to all chapters).
Warnings: Violence, partner betrayal, torture.

Semper Fidelis

Part One

Mycroft Holmes wouldn't believe it. He couldn't believe it. His assistant was a plant? A spy?

But the evidence was right in front of him. The photographs of her on her phone late at night, at times that coincided suspiciously with leaks of important information. A coded communication sent from her personal computer, detailing his schedule, such as it was, with suggestions for assassination timing and methods.

His first, visceral instinct was to reject it. No, not her. Not the woman he...

But he swiftly corrected himself: such methods were common. It had been the downfall of many great leaders in the past – emotional attachments. Send someone who is at first so devoted they can't help themselves from confiding in them, can't help themselves from spinning their plans with them, can't help themselves from keeping them close...

Can't help imagining themselves in love with them...

And then the spy begins to do their work, and by this time the target is so enamoured of them that any evidence against them is dismissed out of hand. Suspicions are brushed aside, rumours of betrayal are scoffed at, and eventually the target is right where the plant wants them.

Since they'd commenced an intimate relationship, how often had Mycroft wondered at his luck? After all, the various necessities of running governments didn't make him the most attentive of partners, and though his affection might have biased his judgement Mycroft was certain she wouldn't lack for suitors. He was well aware there were many better options available to her, and it had been a puzzle as to why she'd chosen him.

It was horrifying how plausible this made her motives.

In the instant he registered that horror, that aching sense of loss and the screaming pain of betrayal, Mycroft shut it down. He closed his eyes, breathed deeply and evenly, and didn't open them until he'd pushed that complicated tangle of love and fury and pain into the bottom of his stomach. Until he felt nothing for contempt for himself for falling into her plot.

Strangely, it wasn't the fact that they'd had sex that made her betrayal seethe like acid in his chest, but the intimacy surrounding the act. The quiet dinners that were a unspoken prelude to more, the breakfasts eaten together in the early hours after a sated sleep, sometimes consumed in the bed itself if they were feeling especially decadent that morning...and all that time, she was plotting to kill him.

And if he'd died, she would have had everything. Mycroft's contacts would have become hers, his protection hers as well...

He tried to be thankful that the message had been intercepted by one of his spies. It had been pure chance the man had found it, as it had been quite deliberately routed so that it wouldn't come into contact with him. Which, really only made it all the more damning – only he and his assistant knew the identity of that particular plant, so only she could have plotted so neatly to avoid him.

Mycroft took another deep breath, struggling to compose himself. In ten minutes, she – and it would be 'she' from now on, he wouldn't let himself think of her name – would come in, and he had to be ready.

For a moment, he wondered if he should have one of his many bodyguards actually present in the room in case she attempted to kill him when she realised her carefully planned assassination was going to fail. But in the end he decided against it; she wasn't expecting her cover to have been blown, and was unlikely to be carrying any weapon he couldn't defend himself against.

And his bodyguards might object to what he was about to do.

Mycroft didn't waste any time – it would have to be quick and clean, like amputating a gangrenous limb. He started speaking as soon as she opened the door.

"You employment is now terminated, and I suggest for your own sake that you leave the country."

Where someone else might have started, might have rocked back on their heels, she simply blinked. "I-"

"It's no use protesting," Mycroft interrupted. He couldn't let her plead her case – he didn't trust his resolve to go that far. "We know where your true loyalties lie."

Before, she had been nothing but confused. Now he saw the slight shift in her expression – the tilt of her mouth, the way she held her head – that told him she'd realised he was serious.

"However, while you haven't been loyal, you have been helpful," he mused, trying to justify what he was about to do. "And I feel some kind of payment is owed for...services rendered..."

Mycroft's smile felt like the edge of a knife, rigid and cold. But this was good, this was right – he would reduce what had been between them to nothing but a distasteful transaction.

He steeled himself against her expression, telling himself it was all part of the act. Of course she would look shocked and devastated, of course she would look at him like he was the one who had betrayed her, so that he might take her back and proclaim it all a horrible mistake, so she might continue her work...

"You have one day's head start," he finished.

Mycroft knew this was foolish. He was allowing her an opportunity to return to her employer with whatever information she'd gathered on him...but at least this way, they had a chance of tracking her back to whatever nest she'd emerged from.

And no, it most certainly had nothing to do with the fact that he didn't think he could bear to see her dragged out of his office.

She stared at him for several moments in seemingly-dumbstruck silence, then proved that for all her treachery, she'd never been a stupid woman.

She ran.


"I'm sorry," Lestrade said.

"Why?" Sherlock asked, pleased that his voice sounded almost normal. "Unless you, too, are working for Moriarty."

"Well, I know you were...fond of him," the inspector said awkwardly.

Sherlock had the sudden, irrational urge to laugh. 'Fond' of John? He supposed he was 'fond' of John in the same sense that an oil fire was 'lukewarm'.

He stared down at the evidence Lestrade had brought, the CCTV stills and phone records scattered across the coffee table, and felt suddenly ill. He wondered if the strange wrenching sensation in his chest was a symptom of a heart-attack, and all at once hoped that it was, and that it would kill him. Because if he dropped dead on the living room floor, then he wouldn't have to keep sitting here, staring at...at that.

Phone records, photographs, times and dates of meetings...a vast collection of evidence that all demonstrated one thing – John was working for Moriarty. Had been working for Moriarty since the beginning.

Sherlock didn't want to believe it...but the evidence was undeniable.

It also explained some points that Sherlock was been curious about. It explained why Moriarty had come into the picture so soon after meeting John – he'd waited until his spy was in Baker Street to make himself known. It explained why the bomb at the pool was fake, why Moriarty had simply laughed and walked away afterwards, saying something about it being a test. Apparently it had been a test to see if John had successfully infiltrated.

And more than that, it explained why, when Sherlock had dragged him off those chlorine-stained tiles and kissed him, John had kissed back.

He'd never understood why until now. Sherlock knew what he was – a narcissistic genius with a borderline personality disorder – and he'd no idea why John – who, in spite of his sometimes-hot temper, was probably the most open, accepting and generous person Sherlock had ever met – would want to engage in a relationship with him. But he'd wanted to; indeed, he'd seemed almost eager to.

They'd been engaging in sexual intercourse for three weeks and five days, and John had yet to lose the almost reverent expression that flitted across his face when they shed their clothes, as if he couldn't quite credit what was happening. He'd looked like a man who could never truly believe he was this lucky, this fortunate, and it had always seemed bizarre to Sherlock – if one of them was going to be counting their blessings, shouldn't it be him?

But now...now he knew that expression had been John wondering at his luck that his target trusted him so implicitly, that he'd advanced so far into Sherlock's inner circle.

It was just like what had happened with Sebastian. They were always out to get something from him, and he'd been confused when John didn't seem to want anything...but now, it all made sense.

"We've got some units looking for him," Lestrade went on. "Do you know where he is?"


"Sherlock, this is serious-"

"So I see," Sherlock snapped, indicating the evidence Lestrade had presented with a broad sweep of his arm.

Lestrade frowned. "Don't think you can protect him."

"Why would I want to protect him?" Sherlock asked, pleased when his voice remained steady. "If he's working for Moriarty, then I want him in prison just as much as you do."

The look Lestrade sent him was overflowing with doubt, but there was no reason for him to remain and he knew it.

"I'll leave a watch on the flat," he said as he left. "He doesn't know he's been sprung, so he's bound to come back sometime."

Sherlock nodded absently, staring fixedly into the kitchen and trying not to remember the fact that John had wanted a cup of coffee after they'd had sex that morning, and had made it while he was still naked. At the time Sherlock had been strangely enchanted by it, by how comfortable John was with him (though the view might have had something to do with his appreciation as well), and now...now he just felt ill.

He allowed for ten minutes to ensure that Lestrade was truly gone, and then he acted.

Sherlock took John's gun and three magazines of bullets and stuffed them into a tattered bag Sherlock suspected John had carried to Afghanistan, along with every piece of clothing the doctor owned. Then he left the flat – it was child's play to shake the policeman who'd been tailing him – and made his way to Tesco's.

Sure enough, there was John, just stepping out of the shop with a plastic bag filled with perishables. The sight sent a strange feeling juddering through Sherlock's chest, as though someone were twisting at the sinews and ligaments that supported his heart and lungs.

He walked straight up to John, ignoring the cheerful greeting that made bile rise in his throat, and ripped the plastic bag out of his hands, shoving the tattered duffel into them instead.


John blinked. "What?"

"You've been found out," Sherlock gritted out. "Run."

"Found out?" John echoed. "Sherlock, what are you-"

"I know you're working for Moriarty!" Sherlock spat, shoving his hands into his pockets before John (if that was even his name) could see them shaking.

John gaped at him. "Working for...have you gone mental?"

Sherlock had to give him credit – that was truly a flawless imitation of bewilderment and hurt.

"The evidence is undeniable – you can't bluff your way out of this one," he hissed. "I've just given you your gun and all your clothes, and if I ever see you again, I won't hesitate to turn you in."

With that, Sherlock spun around and all-but ran away.

Sherlock knew he should have turned him in, should have told Lestrade he was at Tesco's and let the police do the one thing they were good for and arrest him. But he couldn't bear to think of John in prison, and if he gave the man a head start and everything he needed...there was a chance he'd never have to see him again.

And like that old saying went – out of sight, out of mind. If he never saw John again, perhaps he'd someday be lucky enough to stop thinking of John.

To stop seeing the moment before he turned away, when John stared at him with hurt and betrayal written across his features as though Sherlock was the one who'd turned on him.


John had never quite understood the term 'pole-axed' until now. He watched Sherlock sweep out of sight with a numb feeling of unreality – this was a joke, right? It had to be one of Sherlock's weird experiments.

'All right, calm down,' John told himself. 'Just go right on back to the flat and explain to Sherlock that there are some things you don't experiment with. Everything will be all right, just go back home.'

But as soon as he stepped out on the pavement, a black car pulled up beside him. It was smaller than Mycroft's usual, and it was the passenger door the opened for him rather than one of the back ones, but John wasn't in a mood to be choosy. Maybe Mycroft could explain why Sherlock had done...that.

Except there was no generic, perfectly professional driver waiting for him. It was the woman whose name wasn't Anthea, and she was looking a bit...well, frazzled.

"Hello...erm, Anthea?" John hazarded.

There was a small pause, and Anthea seemed saddened, as though she'd just had a particularly depressing thought.

"That will do," she said eventually, and something in her tone made the back of John's neck prickle.

He opened his mouth to ask what this was about, but Anthea spoke before he could, pulling away from the curb.

"I've collected you, Dr. Watson, because I feel we may be in the same boat, so to speak."

"Mycroft's done some crazy experiment about loyalty, too? And please – call me John."

Anthea glanced at him from the corner of her eye as she negotiated the traffic, and the expression on her face looked uncomfortably like pity. "John...that wasn't an experiment."

Something deep and vital in John froze as though it had been plunged into liquid nitrogen.

"I believe both of us have been framed," Anthea went on. "And the coincidental timing suggests we were framed by the same person."

John barely heard her. Her voice was muffled by the shrieking denial ripping through his brain.

"No! NO! Sherlock trusts me, he wouldn't-"

"He did, John!" Anthea snapped. "Just as Mycroft did!"

Her following silence was heavy with grief and fury, and John saw some of his own heart-shattering pain glimmer in her eyes as she stopped at a traffic light.

In spite of the fact that she was obviously finding this as difficult and agonising as he was, John couldn't help himself asking, "Sherlock really believed that? Without even giving me a chance?"

A sigh that felt dangerously close to a sob shuddered in his chest. "He didn't even talk to me..."

There was no appreciable change in Anthea's expression, but her voice was gentler when she spoke again. "I hacked the police records, John – the evidence is quite overwhelming."

John absorbed that information the way he would have absorbed a sudden blow to the gut – with pain and incredulity.

Sherlock hadn't even given him the benefit of the doubt. Instead, he'd believed what he'd been handed, and hadn't even given John a chance to defend himself. And here John had thought he'd actually meant something to Sherlock, that the other man had cared about him...

John swallowed harshly, stifling the grief and betrayal and fury that had risen in his throat. He took a deep breath and let it gust from his lips, feeling the strange calm that always descended on him in crisis situations rise to the fore. He closed his eyes and embraced it, only opening them again when he was certain he was in control of himself.

"So," he said quietly, his voice carefully blank. "What now?"


She'd struggled not to react when Dr. Watson – John, she reminded herself – had called her 'Anthea'. He hadn't intended it as a deliberate slight, but it had rubbed salt into a raw, still-bleeding wound. Only one man still living knew her real name, knew her...but here, to John, she would be Anthea. She would be Anthea until she'd dragged herself out of this.

Originally, she'd only hacked the police records in an effort to determine if any one of the numerous people she and Mycroft had put away for corruption had been released recently. She hadn't thought it likely, but had been trying to determine who might have a motive to frame her for betrayal. And she'd discovered that she wasn't the only one being falsely accused.

Anthea knew it was possible that the evidence against John was completely sound and he truly was working for Moriarty...but it all seemed a bit too coincidental for her tastes. She hadn't been sure about going to pick him up – he didn't seem the cloak and dagger type, and was more likely to be a dead weight than not...but they might as well stick together and he had good reports from the army, so he'd be at least semi-useful in this situation.

Though it looked like he wouldn't be useful for a while yet. John still looked dazed and...well, broken, as though every particle of his being was struggling to reject what he'd just been told and what Sherlock had just done.

Anthea couldn't deny she felt a reluctant stirring of sympathy. Two hours ago, that had been her. Standing in the office she'd worked in for years, staring at the man she'd thought she'd known while he banished her from his life...

She jerked her head roughly from side to side, keeping her eyes fixed on the road and trying to drown out the memories. She wouldn't think of that, not now...

"So, what now?" John asked, his voice surprisingly composed.

Anthea glanced at him as she idled in traffic. John's face was perfectly flat and almost expressionless, only the lines around his mouth and at the corner of his eyes betraying his tension.

She was actually impressed – John had been betrayed not five minutes ago, and he'd already moved past his initial emotional response to action. He might be useful, after all.

"Now, we plan," she said shortly.

Mycroft had promised her a day's head start, and she was going to take full advantage of that.


AN: Thanks so much to my beta, ginbitch, who helped me clean up this chapter! Also, the title 'Semper Fidelis' means 'Always Faithful', which I thought was appropriate.