Margaux decided to deliver lunch to Molly. She knew her well and was almost certain that if she were too busy to leave the lab, that meant her lunch would consist of a cereal bar and a fizzy drink from the vending machine.

She joined the queue in the hospital cafeteria and took her phone from her pocket as she waited.

'How are my two favourite boys? I am of course referring to Vaughan and John.' She sent her text with a grin.

After a moment, her phone buzzed in her hand.

'Ha. Ha. Ha. Hilarious.' Even his texts dripped with sarcasm. 'John isn't here and I haven't seen Vaughan in a couple of hours. I assume he is fine.'

'Well that's not concerning?'

'What you just said was not a question. Why the question mark?'

She huffed as she read his text, shuffling up the line as she typed her reply. 'Here's a question: Where is my son?'

'Sleeping downstairs.'

She let out a giggle as a mix of realisation and relief washed over her.

'I'll be home soon–' She stopped typing, deleting her words slowly. 'I'll be at your flat soon. Just taking Molly some lunch x' She stepped up to the counter, ordered and paid, before checking her phone again.

'Lunch sounds good. Bring lunch.'

Margaux put her phone away and stood aside as she waited for her order. She glanced up to see a familiar dimpled smile approaching her.

"Margaux?"

"Doct– Oliver? Hi!"

Oliver Grant hadn't changed at all in the years since she had last seen him, except for the horn-rimmed glasses that now adorned his face. He pushed them up his nose as he spoke.

"How are you?" he asked.

"I- I'm… yeah I'm good. How are you?"

"I'm good too. Wow, I can't believe I've ran into you here. When I stopped seeing you around I assumed you'd moved away or something."

"Oh, no I left the investigative field for a while."

"Ah," he nodded. "So, what do you do now?"

"Erm well…" she cleared her throat. "If I told you I'd have to kill you."

Oliver burst into laughter. Margaux thought about when she used the same joke on Sherlock at dinner; You're terrible at this, he had said, his face cold and stern. But Oliver was warm with genuine amusement, even though her joke really was terrible.

"What about you?" she continued. "I've been visiting the labs for a while and haven't seen you around."

"Yeah I just transferred back last month. I was working over in Essex."

"Oh really? Why Essex?"

"I, er, I moved to be closer to my girlfriend."

"Oh," she nodded as she took her order from the server. "Well," she continued, gesturing to the cartons of hot food in her hands. "I better get this up to Molly. It was nice seeing you, Oliver."

"You too," he smiled. "Actually, Margaux… I just finished for the day. Do you want to go for a coffee? We never did go on that date."

"Oh, I'd love to but I can't, I have to head straight home." She said it again. Home. Why did she keep calling it home?

"Well if you want someone to sit with at the bus stop, I'll be there," he smiled.

III

The car pulled away from the kerb smoothly. Mycroft settled back and pulled the seatbelt across his front. That didn't go well, he thought, as he watched London go by through the tinted window. Sherlock's anger had almost been palpable, and his need to protect Margaux and his son was almost instinctive, second nature. As if his ability to feel had lay dormant for his whole life, and Margaux had woken it.

He thought back to his conversation with her, in the café almost a year ago:

"My brother is reckless. He lacks empathy. He's a loner, an addict, and I think your son–"

"Who is also your nephew."

"Would do better in his absence."

He sighed at the memory; the harshness of his words.

"It is how we work best, Margaux. From a distance."

Perhaps he was wrong.

III

Margaux rummaged through her bag as she stood in the middle of the street. Her hair blew wildly in the ferocious wind, catching in her eyelashes and sticking to her balmy lips. She grabbed a stray hair tie from the bottom of her bag and pulled her hair into a bun before continuing her walk down the street. She caught a glimpse of her reflection in a shop window, wondering why she could never seem to achieve the 'effortless up-do' effect that so many women had mastered. Instead, she approached the bus stop feeling as though she resembled Miss Trunchbull from Matilda, or Gollum.

"Hello again," a voice appeared beside her.

She turned to see Oliver standing with his hands in the pockets of his buttoned-up coat.

"Hi," she smiled.

"You suit having your hair pulled back," he said sincerely.

"Oh, thanks," she replied before double checking her reflection in the bus stop window; nope, still Gollum-like.

"So," Oliver continued. "Still can't tempt you with a coffee?"

"Er…"

"You know what, I'm sorry. I'm being totally presumptuous assuming you'd still be single after all this time, I–"

"No, I am! Single, I mean. But…" she sighed. "Oliver it's just not– you see… I have a little boy." And a Sherlock, she added in her head.

He gave a slight nod.

"You don't seem surprised," she said.

"Well after the time you fell and hit your head and that doctor practically forced me to leave the examination, I was concerned because I didn't hear anything about you afterwards."

Margaux shuddered at the memory, suddenly remembering the feeling of a gun pressed against her head.

"So, I went back a couple of days later and checked over your bloodwork to make sure everything was fine. Turns out you were pregnant," he finished jokingly.

"No way! Was I?" she joked back.

Oliver chuckled, sitting himself down on the cold metal bench in the bus stop. Margaux followed, sitting beside him.

"How's motherhood treating you?" he asked.

She shrugged. "It's not something I ever thought I'd do. But I couldn't imagine my life without him now. What about you? Any kids?"

"Nah. My girlfriend and I talked about trying for a baby but we never found the right time. Now she's my ex-girlfriend so I guess it's a good job we never did."

"I'm sorry."

"No, don't be. If that hadn't ended, I wouldn't be here talking to you now." He looked down at her and smiled.

She smiled up at him, feeling a blush beginning to warm her cheeks.

III

Sherlock sat cross-legged on the floor of the living room. Vaughan sat opposite him with his small legs outstretched, watching as his father held up a large poster of the periodic table.

"Now, this one?" said Sherlock as he pointed to a square on the poster.

Vaughan stared at his father blankly.

Sherlock sighed. "It's Iridium."

Margaux walked into the flat and placed a brown paper bag on the arm of the couch, cocking her head to one side as she watched them curiously.

"Right, let's go back to an easy one." He pointed to another square. "Au?"

Vaughan glared at the square for a moment. "Gowd," he finally said softly.

"Good! Yes! Gold!"

Margaux cleared her throat. "Er, Sherlock?"

"Oh, hello Margaux."

"Hi… What are you doing?"

"Well we've surpassed colours, numbers, the alphabet, all the childish stuff–"

"Childish? He's only two."

"I wanted to try something more challenging. The solar system proved too easy so we've moved on to this."

"Again, he's two," she said as she joined them on the floor. "Also, don't think I haven't noticed you trying to brainwash him into loving chemistry."

"Well it's better than 'forensics'," Sherlock air-quoted with a mocking voice.

Margaux raised an eyebrow.

"Sorry," he said quickly as he rose to his feet and walked over to the bag. "Lunch, excellent," he checked his watch. "Though, now it's more of an early dinner."

"Yeah, sorry. I got chatting to someone outside St Bart's. Oliver Grant, have you met him? He's a doctor there."

Sherlock carried the bag into the kitchen and began dishing out the food. His ears pricked, noticing the change in her voice; the way it inflected differently, cracked in the wrong places. She was holding something back.

"I don't believe I have," he said calmly.

"Well he's nice. He seems to still really like me, even after so many years. I think I might invite him to my birthday–"

"Are you coming to get your food or am I to serve it to you like a waiter?" he interrupted crudely.

She stood up with a huff and marched to the kitchen. "Well considering I took a detour on my way here just to pick this up for you, Sherlock, I'd say walking my plate three feet across the room shouldn't have been too difficult of a task."

They sat at the dining table eating quietly, the only sounds being the clattering of forks against plates and Vaughan's enthusiastic mumbling as he picked at his food, most of it ending up on the table itself. Sherlock and Margaux continued to glance at each other, always missing the other's eyes by seconds. She purposely kicked her foot against his leg. But instead of reacting, he simply tucked his legs tighter under his own chair.

"So…" she began. "You're really sulking because I said Oliver fancies me."

"Actually, you said he 'likes' you. But good to know physical attraction is present also," he replied.

"Yes. It is," she said, deciding to fight fire with fire. "I'd almost forgotten what it felt like to be fancied."

"Well I'm pleased for you."

"You didn't deny it… You are sulking, aren't you."

They finally locked eyes, neither wanting to be the first to look away. Sherlock was beginning to understand what John had meant when he said they were a match for one another – fire and ice – her amber and his blue meeting in a fierce glare, almost connecting in the space between them.

Their silent battle was interrupted by Vaughan knocking over his cup and spilling juice down his front. Margaux jumped up and reached for a roll of kitchen towels.

"Oh it's okay, love, don't cry," she said, trying to sooth her now crying toddler. "Sherlock, can you see to him while I clean this up?"

He put his fork down reluctantly and stood up, scooping Vaughan into his arms and removing his wet clothes. He carried him into the bedroom to change him as Margaux patted and wiped down the table and floor.

A knock at the door interrupted her cleaning.

"Sorry," said Mrs Hudson from the doorway, before stepping aside and allowing Greg Lestrade to enter the flat.

"Hi Greg," said Margaux breathlessly.

"Hi, Margaux. Is, er, is Sherlock here?"

Sherlock returned from the bedroom with his freshly changed son still in his arms.

"Sorry to interrupt," said Lestrade as he stepped towards them with his hands in his pockets.

"Oh, don't be, trust me," he replied.

Margaux gave Sherlock a sarcastic smile. Vaughan giggled.

"Was wondering if you'd mind coming down to the station," Lestrade continued. "A teenage girl's gone missing and her parents just received a ransom note."

"I suppose," he huffed as he grabbed his coat. "Margaux, call John and have him meet me there."

"I'm not your secretary."

"Oh just call him, will you," Sherlock continued, before walking out the door.

"Erm… Sherlock, I think you're forgetting something," she called from inside the flat.

He stopped on the landing and turned around. "Hm?"

"Maybe put the baby down?"

He looked down at Vaughan, almost recoiling in horror as he realised he was still carrying him. He put him on the floor and patted his head awkwardly.

Perhaps he was growing too accustomed to the role of a father; his arms had become carriers, his chest a pillow, his hip a seat. His son's presence had become so familiar that as he left the flat without him, he was overcome by a feeling in the pit of his stomach, the sensation that he had forgotten something.