Lonely was a feeling Margaux was used to, but it wasn't one she enjoyed. She had spent her whole life alone; with bad parents and failed relationships, she had learned the only person she could rely on was herself. She liked to leave the television on, even if she wasn't watching; the hum of voices in the background made her feel less alone as she padded around her flat on dark, quiet nights.

She knelt next to the bookcase in her living room, searching the bottom shelf for her favourite book, when she noticed their faces on the television. She walked over and perched on the arm of the couch, lifting the remote and turning up the volume.

"Another case solved and another life saved thanks to the enigma that is Sherlock Holmes," said the news reporter, followed by footage of Sherlock and John at a police press conference.

"The hat's a bold choice, Sherlock," Margaux muttered.

She switched it off and threw the remote onto the couch before walking over to the window and peering through the blinds. She wasn't shocked to see him standing there; his hands in the pockets of his long coat, staring at her building from across the street. He did it most nights; stood there and debated with himself about whether to ring her buzzer or leave, never getting closer than the other side of the road. Always distant. Always brooding. She wondered if he ever noticed her watching him from the window, if he made the trip especially because he wanted to see her, or whether she was a last minute thought as he passed by her street on his way home. She wondered how she would feel if he ever stopped coming.

Margaux woke in the morning feeling groggy. Her head was pounding and her stomach turning with hunger as she flicked on the lamp and checked her phone. The autopsy report she had been waiting for was ready, which meant she would get to spend time at the hospital with Molly. No matter how ill she felt, the thought of a day with Molly was enough to make her smile. She dressed in a knee-length dress and thick, knitted cardigan. She traded breakfast for a cup of coffee and swallowed two painkillers before leaving her flat in a hurry.

III

"Hiya," said Molly as the door swung open.

She pulled off her latex gloves, slid the protective goggles onto the top of her head and turned around with a smile.

"Hi," answered Margaux between deep, painful breaths.

Molly's smile quickly changed to concern. She stepped towards her. "Are you alright?"

"Yeah, sorry, I was half way here when I got a call from my boss," Margaux began, struggling to catch her breath. "There's been a massive breakthrough in the case. The autopsy report you sent over… something isn't right. So I needed to get here before you released the body… So I ran…"

"Okay, well you look knackered, let's get you a seat." Molly grabbed a stool and dragged it towards them. She helped Margaux sit down, examining the pained expression on her face. "Are you sure that's it? You don't seem right."

"I don't know. I missed breakfast and I had an awful headache this morning."

"Right, I'll go and get you a water from the machine."

Molly ran across the hall to the vending machine, pulling the change from her pocket and sifting through it. She put the coins in the slot, pressed the button and waited for the thud.

The bottle wasn't very cold, Molly thought, as she hurried back to the lab. Maybe she should have got some sort of chocolate bar too. Never mind. She opened the door and glanced around the room; for a moment, it seemed as though Margaux had gone, until Molly noticed her lying on the floor. A small trail of blood trickling from her nose.

"Margaux?"

III

They were landing in Sherlock's lap. Case after case. It was as if 221B had grown a revolving door; spitting out clients, one after the other, like a collection of short stories he couldn't put down. But there was a white noise in the background of everything he did. A constant niggle of unease, like something was wrong. Or more so, like something was coming.

He stepped into the flat and was greeted with John's backside waving in the air next to the window. He was bent over looking for something.

"Lovely view, thank you," Sherlock said blandly.

John snapped upright and turned around.

"I can't find my cufflinks. I thought maybe they'd fallen out of my pocket or something. Have you seen them?" John replied.

"No."

"Great."

"I've got a pair, you can have those. I have no use for them, all my shirts have buttons," said Sherlock as he turned towards his bedroom.

"Why do you have a pair if you don't–"

"A gift."

"Oh yes, the art gallery," John muttered to himself as he watched Sherlock leave the room.

As he stepped into the bedroom, he was greeted by another backside. A female, early thirties (though she liked to act like a twenty-year-old judging by her outfit, Sherlock deduced). She was bent over by his bed, the sound of the door startling her. She stood up straight and turned to him.

"Oh hello," she said breathlessly.

"You must be… Rita."

"Yeah, sorry, John said I could use his room to freshen up, I must have come into the wrong…"

There was an awkward silence. Sherlock stepped aside gracefully, allowing a clear path between Rita and the door. She didn't leave.

"Can I help you in some way?" He scrunched his brow.

"Sorry." Her laugh was wrapped in an east end accent. "I've just seen a lot of you on the news, I'm a bit star struck. Only gone and ended up in Sherlock Holmes' bedroom, haven't I!" She laughed again.

But he didn't laugh, and in response, her smile dropped.

Her colder expression took Sherlock by surprise. "My boss is very interested in you," she said calmly. It was like a different person had taken control of her body.

"If your boss needs my assistance then I'm sure he or she could make an appointment to see me, instead of sending their employee to snoop around my bedroom."

"Oh, he doesn't need your help. Quite the opposite, actually." A smirk crept across Rita's glossy lips.

"What does that mean?"

"Rita, ready to go?" John called from the living room.

"Yep!" she shouted back. "Lovely to meet you, Mr Holmes." She walked past him and out of the room.

John peered his head into the room "Sherlock, you got those cufflinks?"

Without speaking, Sherlock stepped to his chest of drawers, pulled out a box – still wrapped – and handed it to him.

"Cheers," said John before disappearing.

III

Dr Grant's face was still blurry as he leaned towards her, looking in her eyes with a torch.

"You might have a slight concussion from the fall but nothing to get too worried about, looks like your poor nose broke most of the fall. Things still blurry?" he spoke softly.

"Just a bit."

"Well your eyes are fine so that should wear off. Have you fainted like that before?"

"A couple of times when I didn't feel well as a kid." She rubbed her eyes. "But y'know, I had a headache this morning so I took some painkillers that were probably way too strong for me and I didn't eat and…"

"Don't worry. It's all just precaution."

She nodded.

"Now… Could I get you to do a wee sample?"

Margaux let out an unexpected laugh before dropping her face into her hands. "This is not what I thought I'd be doing today."

"Well if it makes you feel any better I've just asked my crush if I could have a sample of her piss. So, you know, it could be worse."

Even through the blurriness she could see his dimpled smile. She laughed again, softer this time.

III

She sat on the edge of the hospital bed, listening to the clock. She looked down at her watch and squinted to see the hands ticking around. Dr Grant released the blood pressure cuff and checked her eyes with his torch again.

"Everything's normal. Once your blood and urine results come back, we'll let you get on with things," he said.

Margaux nodded as she rolled down the sleeve of her cardigan.

The curtain slid open, suddenly enough to make the pair of them jump. A tall, blonde man in a white coat stepped in and closed the curtain again behind him.

"Dr Grant, I'm Dr Hartley, I'm taking over this assessment," he said.

"I don't think that's necessary, we're fine here," Dr Grant replied.

"I'm sure Margaux won't mind."

Margaux sensed a shift in the atmosphere. It was uncomfortable.

"I-I'm sorry, I'm slightly confused, who has requested this?" asked Dr Grant.

"Is there something wrong with me?" Margaux added.

"Not at all. I'm just aware that Dr Grant will be needed elsewhere. So I'm going to take over here." He stepped aside and gestured to the curtain.

"Right… well…" Dr Grant muttered. "If you need anything, Margaux, just…"

Margaux nodded before watching him leave. Suddenly wishing she was going with him.

III

Sherlock had said goodbye to another potential client. Yet another case not worth his time. There had been three so far today; two, he solved within seconds of meeting them, the other, a classic case of paranoia. Today was not a good day. His concentration had been hindered by the encounter in his bedroom. Rita. She was strange. She made him feel strange. And now John wasn't answering his calls or texts.

He closed the door on his latest appointment and headed straight for his bedroom; searching it once again. He was convinced she had taken something, or left something behind. But there was nothing. He took out his phone and called John again, and once again, nothing.

"Sherlock," Mrs Hudson called.

"Yes?" he said as he walked back into the living room.

"Another client," she whispered, her head peering around the front door.

Sherlock sighed, "Send them in."

He turned his back on the door and took his phone out of his pocket.

'Urgent. Call at once.' He sent to John.

"Hello again."

He turned swiftly. It was Rita. He wondered if he had ever felt a sense of dread and relief at the same time before.

"Is John with you?" He asked.

"Oh…" She glanced around carelessly. "Must've lost him."

Neither of them moved, the silence agonising.

"Who are you?"

"I'm your next appointment," she answered casually.

"No one would go to the hassle of getting close to John just for the chance of me taking their case. So I'll ask again… Who. Are. You." His intensity was scalding; enough to frighten even the coldest of people.

She composed herself. "I'm just the messenger really. See, I was supposed to have a bigger part in all this, hence dating John and all that. But there's been a slight change of plan; a new finding that's just… thrown everything up in the air really."

"Your boss…" Sherlock paced the room slowly. Then it hit him. "Moriarty."

"Spot on," said Rita, touching her nose.

"Where is John?"

"Who do you love the most?"

"What have you done to him?"

"He's fine, god, can you just answer my question… Who do you love the most?"

"Will you shut up with your ridiculous questions and just get to the point," he snapped, frustration seeping into his words.

"Was just trying to build a bit of tension! Drama and all that," she sighed. "Moriarty sent me to tell you that he's waiting for you, and that he's already played his first move. There, done." She waved her hands around and headed for the door.

"Waiting for me where?" asked Sherlock as he followed her onto the landing.

"Aren't you Sherlock Holmes? You ask a lot of questions for someone who's supposed to already know everything. He said the game has to start where it will end."

Where it will end. What did he mean? Sherlock placed his fingers on the sides of his head and closed his eyes. Think. Think!

"Tell John I'm sorry it didn't work out," Rita called from the bottom of the stairs.

III

The game had to start where it was going to end.

Sherlock stood on the street outside St Bart's Hospital. He shielded his eyes and looked up to the roof, the pale grey sky, the clouds of smog. He followed the building down; every brick and every window until he reached the pavement. He flicked up the collar of his coat and went inside.

'The game has to start where it will end.' He replayed the words over and over as he walked through the corridors of the hospital, pushing through doors and running down flights of stairs. All the way down until he came to the morgue.

"Molly."

"Oh, hello Sherlock." She smiled, her eyes widening with excitement at the sheer sight of him.

"The basement. The very bottom of the hospital, is that still out of bounds?"

"You never just come to visit me, do you."

"Molly."

"Yes, it is. There's some rooms down there where they store things but there's been a lot of water damage, a leaky pipe or something I think, it's damaged the foundations but then again it could– "

"Molly."

"Sorry. Sorry, yeah. It's out of bounds. The maintenance guys aren't even allowed down there now." She picked up a pair of gloves and stretched them over her hands. "Why?"

She looked up. He was gone.

III

The doors of the lift opened into almost darkness. Sherlock stepped out, the concrete floor was cracked and wet.

"John?" He whispered tentatively as he walked. "John?" He whispered again.

"Sherlock?" John's voice came from further down the hall.

He rushed towards it, his shoes splashing in shallow puddles as he ran.

"About bloody time." John whispered as Sherlock came into view. He was attached to a pipe with a pair of handcuffs.

"I don't even want to know how you got yourself into this," said Sherlock as he examined the cuffs.

"Shut up and just get them off me."

"Here, this may help." A soft, calm voice called out.

A few feet down the hall stood Moriarty with his hands in the pockets of his clean, expensive suit. He pulled a hand from his pocket to reveal a small key. He threw it to Sherlock who caught it with ease.

"Now player one is here, we can get started," he said before opening a door and disappearing into the room.

Sherlock unlocked the cuffs and stood up, following Moriarty.

"What are you doing? Let's just go!" John shouted.

"There's more to this, I can't just walk away."

"Last time we came face to face with that lunatic, we almost blew up. So yes, you can and you should walk away."

They stood staring at each other for a moment. Finally, john rolled his eyes, let out a sigh and headed towards the room with Sherlock.

"It's handy to have lots of eggs in lots of baskets," Moriarty began as they stepped into the room. "It means when you need a place to orchestrate an elaborate plan, you've got people who'll cordon off an entire hospital basement just for you." He smiled.

Sherlock looked around the room. It was packed with old equipment and furniture, nothing remarkable except a large mirror extending the length of the wall behind Moriarty.

"Don't get me wrong, as you can see there has been a bit of a flood. Hope you didn't wear your nice shoes. But nothing a good plumber can't sort out– "

"What do you want?" Sherlock interrupted.

Moriarty rolled his eyes before continuing. "This used to be a viewing room way, way back in the day. Medical students would all come in here to watch live autopsies. Isn't that interesting."

"Not really. Basic knowledge," Sherlock quipped.

John shook his head.

"The point is… Look at the trouble I've gone to for you. And at first, I wasn't doing things for you, I was doing them because I was fascinated by you. What I wasn't expecting was for you to get off on it. To revel in it."

"I revel in stopping you–" Sherlock began.

"No. You don't. Otherwise you wouldn't be standing here right now. No, it's the glory. It's like a drug… I have become your best fix." Moriarty spoke through his teeth. "But this little cat and mouse thing we've got going on, it got me thinking. Is there anything important enough to you that would make you finally put an end to this. To me?"

He flicked a switch on the wall, causing the mirror behind him to become transparent. The room on the other side was dark, Sherlock and John squinted as they tried to make out the shadow in the middle of the floor. Moriarty turned around, noticing the darkness.

"Oh," he laughed matter-of-factly, and flicked another switch which brought the room to light.

"Margaux." Sherlock's lips moved, though his voice was almost inaudible as he stared through the glass.

She was sitting in what looked like an old dentist's chair; her arms and legs strapped down, the dried blood from her nose still visible above her lip. She was terrified.

"Sherlock? Sherlock!" she cried out as her eyes focused on the men behind the glass. "Help me."

"I mean, I'm obviously not talking about her," Moriarty began. "She's not important to you. But Sherlock is important to Sherlock. Sherlock saves Sherlock. So I'm thinking that a piece of Sherlock may be just as impor… Oh I'm sorry, I just realised you all don't have a clue what I'm talking about do you? Okay just give me a sec."

In one fluid movement, Moriarty unlocked the door connecting the two rooms, stepped through and locked it from the other side. With each slow, menacing step he took, the more Margaux struggled to break free. He leaned down next to her and stroked her hair.

"Relax," he whispered before rolling a machine out from under the chair. He grabbed the hem of her dress and lifted it up to her chest. "This is going to be a bit cold," he said, mimicking an old lady.

Margaux could feel the straps digging into her thighs as she tried to struggle free. A sudden cold across her stomach took her breath away. There was nothing she could do, except wait for Sherlock to do something. Moriarty lifted a small device and pushed it hard into her stomach. She gasped and let out a small cry as he slid it around.

A heartbeat.

Moriarty turned to Sherlock with an open mouth. "Oh how exciting," he said excitedly.

Margaux shook her head. No. This was part of his plan. It had to be. She couldn't be.

"There's a part of you, in there. And I could just…" He pulled a gun from his pocket and pressed it against Margaux's temple.

Margaux gasped. She shut her eyes, bracing for it.

"Whoa! Stop! Stop!" John shouted, bashing his hands on the glass. He turned to Sherlock. "What are we going to do? He's obviously after something so what is it? Figure it out!" John ran to the door, throwing his entire body against it. He stepped back and ran at it again. Nothing. He began to kick it, searching the room for things to break it down. All the while, Sherlock stood still. Like he wasn't really there; a ghost, with eyes fixed on Margaux and every case he'd ever solved sifting through his mind.

"You sent the texts. The threatening texts to the imposter. That was you. Trying to get police attention so I would solve the case," he finally spoke.

"I was helping you," Moriarty replied. "Like I did with those people; the fake painting, the missing man–"

"By tying bombs to people's chests – to John's chest."

"You work better under pressure. When there's glory at stake. You work better when there's something. In. It. For. YOU!" He screamed.

Margaux jumped.

"You didn't care about those people," Moriarty continued. "You didn't care about the man who was killed by that faker. You don't care about the victims of these crimes you help solve. But you cared about John. And that got me thinking… What is Sherlock Holmes' Achilles heel? Well I thought it was him so that's why I sent Rita in. But then this happened today and I just thought… oh how poetic. How perfectly, beautifully timed. A little speck of dust that has found its way off of you, flitted through the air, and against all odds, settled itself on her. A cluster of cells and nerves with arms and legs and a beating heart containing… you. I mean in all honesty I didn't think you'd have it in you to even–"

Suddenly, Sherlock let out a scream, slamming his hands against the glass.

"Don't let him get to you, Sherlock. You have to figure something out or she will die!" John shouted, still trying to break down the door.

"I can't… I…" Sherlock began to think.

It has to start where it will end. That was what Rita had said. The game had to start where it would end. This was the start. There was no way out but to play. He took his phone from his pocket, keeping it out of sight, and opened a new text to Mycroft.

'St Bart's Basement. Moriarty.

S.'

He had to stall.

"It doesn't matter what I say, John. He already has our story written out. He's already set up the game," said Sherlock as he watched a smile begin to grow on Moriarty's face.

Margaux's chest grew tight, she couldn't breathe and it hurt. She was having a panic attack. The pain grew stronger, radiating from her chest to her throat and triggering another pain, one she had never felt before, in her abdomen. She let out a scream, it echoed in the pit of Sherlock's stomach.

"I accept," said Sherlock. "I will be a piece in your narrative, I will play your game."

"What game!?" Shouted John as he charged for the door.

"The game, John. Sherlock vs Moriarty. The story in which the moral is to show me my weakness. In which he triumphs… The story where I am exposed as the selfish, sick man who gets off on other people's misfortune."

Margaux screamed again. She was certain she was dying. Moriarty peeled his eyes from Sherlock to glance down at her. Noticing the blood, he let out a whistle.

"Oh dear. Good job we've got a doctor on sight ay? Ha." He gestured to John.

Sherlock began to panic; he needed to get to her. "I'll play," he said, glancing at the hinges of the door. "Two more kicks of this door and it'll be down." He spoke the words to John, but it was almost as if they were aimed at Moriarty.

John ran at the door again, causing the frame to splinter and crack. He stepped back, gave it one final kick, and sure enough, it fell to the floor. Sherlock watched as Moriarty ran to the light switch and plunged the rooms into darkness. Then he felt a breeze skim past him scented with his cologne. He was gone.

Sherlock searched for the switch and turned the lights back on, watching as John rushed to Margaux to free her from the straps. He ran into the room and quickly to her side. He clasped her hand.

"She's bleeding. We need an ambulance now," said John.

III

She wondered if she was strange for feeling grief. Either way, she felt it. She looked down at the cannula in her hand as it rested over her flat stomach and felt guilty. She was sure there was a part of her that would always feel that way.

Sherlock stepped into the room, closing the door gently behind him. He walked over to the hospital bed where Margaux lay and sat in the chair next to her. Neither spoke. As usual, they didn't need to. But she was finding him hard to read.

"I swear I didn't know." Her voice was raspy.

"I know," he said calmly. "Have they said anything? About…"

"Not yet. But they're pretty sure it's gone," she said, trying to give a small smile as a tear escaped the corner of her eye.

"I'm sorry."

"I'm sorry too."

They sat in silence for a while longer, until visiting hours ended and he had to leave.

A knock on the door came soon after, somehow she thought he had snuck back in and became disappointed when she was greeted with a smiling doctor.

"Margaux Cave?"

"Yes."

"I have some incredible news for you."

III

Margaux had been discharged from hospital and taken home by a team of Mycroft Holmes' most trusted employees. She closed the door and double bolted it immediately, and now she found herself alone with the television again. She stood next to her bed with her phone in her hands. Just call, she thought. You want to talk to him so just call. Suddenly, there was a shift in the room; it felt fuller somehow, and his clean scent surrounded her.

"I thought I locked the door," she said, her back still to him.

"Window."

"That's breaking in. It's against the law you know." She turned around.

"I didn't think you'd mind." His voice was low and serious, almost troubled. She had never seen him like this.

"Sherlock, are you okay?"

He stepped towards her, his movements so smooth it was as if he was floating.

"I just… I just came because I wanted you to know. That this." He placed his hands near her stomach. "This would have been… a really good thing."

Margaux inhaled. The emotionless, socially inept Sherlock Holmes was being sincere, desperate to touch her, trying his best to articulate how he felt. She cupped his face in her hands, but instead of saying what she was going to say, she just smiled.

"I know," she whispered.

He left shortly after. She locked the door behind him and walked over to close the window. She watched him step into the street and hail a taxi. She watched him climb in. She watched the lights of the cab disappear around the corner.

She would tell him. But not tonight.