"Five," Mycroft muttered into Molly's ear as they entered the wood panelled reception room at Sir Humphrey's luxurious townhouse. She smiled at their host as they went through introductions ("No, no, just old friends, but pleased to be here, sir."), and once they'd found a quiet corner and a drink he elaborated.

"Five exes here," he said quietly, taking a deep pull of his drink. There were cracks forming in his perfect public composure.

"Who?"

"Someone I had a liaison with in my early days, back when an affair of that sort would end your career. I haven't seen them since 1993, when we worked together on a job in Helsinki.'

Molly scanned the room and found an extremely handsome man in his early fifties glancing their way.

"Silver fox at 4 o'clock?"

"Mmhm," he agreed, finishing his drink. She handed him hers.

"Gorgeous. Think he'd be interested in a threesome," she asked after he had taken a particularly large mouthful. Gin and tonic sprayed out of Mycroft's nose, and Molly quickly turned him around to face a wild painting of a fire over an ancient city located behind them, and gestured at the artwork speaking loudly about the colours until he had himself in hand.

"I'm sorry, my dear, if I remember correctly his interests were strictly same-sex."

"The world needs more bisexuals," she sighed, "you're too rare a bird, Mycroft."

"If you're ever wondering what gin feels like in your nasal cavity," he finished by pointing to the scorching scene on the canvas. She took the alcohol-soaked handkerchief out of his hand as he debated what to do with it, not wanting it back in his pocket, and she tucked it into her handbag.

"So how would you like to play this?"

"It's been a very long time, and it's a different world now. That said, discretion as always," he said firmly, his demeanour returning to his cool, public mode. She put her hand on his elbow in a highly ladylike fashion.

"Alright, let's go introduce me to some tedious people, and I'll try to guess the ones you've rogered."

"Dear god woman, behave yourself," he whispered.

They made it through cocktails and dinner without much fuss. Mycroft enjoyed watching Molly enjoy the novelty of the evening, and he enjoyed the novelty of her unique spin on all the usual conversations. When people would ask her things like where she intended to take her holidays, she'd freely admit she intended to spend them with her cat watching Netflix. Where were her people from? Mostly Whitechapel, it was hard to tell before that, really. What sort of school did she go to? The kind that gave her a full scholarship based on her academic success.

Mycroft relaxed, watching her laugh with the CEO of an environmental development firm during dessert. The two brilliant, highly skilled women had seemed to bond over a shared love of a television show about singing teenagers.

"May I join you, Mr Holmes," said a quiet voice over his shoulder. The seat next to him was vacant, Mr Abel having broken a great deal of wind had at last disappeared into the toilets and not reemerged.

"Please," Mycroft answered, collected Mr Abel's napkin off the chair and shifting over to give him more room. Down sat his former lover. "I was surprised to see you tonight, Conor. What's brought you out of Belfast?"

"Business, I'm here as a guest of Lord Whitely. Keeping well, Mycroft?"

"Indeed, indeed. And yourself?"

"Five kids keep me busy," he smiled. He showed Mycroft a photo on his phone of his family at Christmas, his husband holding the youngest, a toddler, high up to place the star on the tree. "We married in Vancouver, ten years this October. Sean's a dentist, but the kids love him anyway. Your wife is a pathologist, I hear? That's fascinating, she must have many stories."

"Molly and I aren't married, but yes, she's quite fascinating herself. We've been friends for sometime and I'm rather fond of her." He absently poked at the pudding with a spoon. "We seem to understand each other, I've come to realize that's an extremely rare thing."

"Britain always was your first love," he stated. Conor leaned closer, and Mycroft saw Molly watching them closely from the corner of her eye. He thought he saw the tiniest wink. Conor continued, very softly. "If you've found someone willing to be second place in your heart, don't let them go."

The hostess called an adjournment from the table, and in the shuffle, Molly found Mycroft again.

"I think I've identified the other four, besides our silver fox," she whispered, casually taking his hand while they made their way through to the sitting room.

"I will neither confirm nor deny," he told her.

"For every one I guess wrong, I'll describe an undergarment I'm currently wearing."

They found a quiet corner of the room, far from the strings quartet currently the centre of attention near the fireplace. She listed off the four names, and he shook his head.

"You owe me one," he responded.

"Which person was wrong?"

"Payment first."

She smirked, and leaned closer to his ear.

"It's for the best that I only got one wrong, because this dress looks best with nothing on underneath."

He nodded at a passing gentleman, greeted him briefly. Molly leaned back in.

"So that means the only thing I can describe are my hose. You can see that they're black and shear. What you can't see is that they're topped with black lace, and they only go up to here." She took his hand and brushed it against her mid-thigh.

"You got Lady Smallwood wrong," he said coolly, trying to assert his self-control. "We've never been involved. The fourth woman was your new Glee buddy, Kate."

"Interesting!" Molly responded. "Well done you, she's lovely."

"She thought I worked too much, she expected me home at 6pm every evening, and all weekend."

"Good luck with that," Molly snorted. "I certainly couldn't keep those hours. I co-authored a paper on bile coagulation last winter that kept me busy for at least twenty hours a week on top of my shifts and extra work for Sherlock and Lestrade."

Mycroft remembered Conor's family photo.

"Perhaps with our complete lack of work-life balance, we should be taking more precautions to prevent accidents," he offered seriously.

"You make room in your life for the things that count," she responded airily, "I'm sure we would make it work." She turned to read his face. "Of course, if it's important to you, we absolutely can."

He gazed down at her from his extra inches, examined her face, and ran it over in his mind. She doesn't want that door to close.

"You're right, we would make it work. I'm not concerned."

Her simple, stylish black dress was skimming against his hand, the fabric unbelievable soft and smooth.

"What does concern me," he continued, "is how this dress will fair once we leave this party. Did we decide whether to yours or mine?"

"This is your party, your night," she said congenially, joining the polite applause as the quartet finished a particularly complicated piece. "What's your desire?"

"Fancy being taken from behind on the grand staircase in my hall the moment we arrive? Leave everything on?"

She made a noise of interest.

"That sounds like a delightful start to our night," she agreed.

MHMHMHMHMHMHMHMH

"You've really never seen Phantom? Play or film?" Molly adjusted the mask over his frown.

"I'm aware of it," he said blandly, feeling ridiculous. "I've read the book."

They were outside the door of Tom's flat in full costume. He grudgingly admitted that Molly looked quite fine in her romantic white Christine dress, her hair curled and pinned in a manner she assured him he'd enjoy removing later.

"Has the irony of this pair of costumes occurred to you? A couple who aren't really together, have nothing in common except passion, and they're both a bit mad?"

"It seemed appropriate," she said curtly. She took a deep breath, and knocked on the door. "Let's just make it through the next hour, then we can leave and never speak of it again."

He took her hand and gave it a reassuring squeeze as the door opened.

"Molls, you made it!"

Tom greeted her with a one-armed hug so he didn't spill his drink, and planted a wet kiss on her cheek. He wore a green morph suit with the face left exposed, and a kilt.

"This is my friend, Mycroft. What are you supposed to be?"

The men shook hands briefly.

"Aw, Desiree backed out last minute, and I couldn't think of anything, so I went with what I had in the closet. Wait, Mycroft? Mycroft Holmes? Sherlock's brother? You're going out?"

"We're friends, Tom, no need to speculate," she said in a cautionary tone. He shrugged, and pointed them towards the drinks on the kitchen counter.

The flat was packed with people, all in their fancy dress, and Mycroft was glad for the mask that gave him the ability to be free with his facial expressions. The music was irritating and loud, the conversations he overheard shrill and irrational.

"This hardly seems like your scene. However did the two of you get as far as engaged?"

"He was kind, decent, attentive," she said with a shrug. "Easy to live with. Life was very pleasant with him, for a time."

A drunk man wandered up to them and threw his arms around Molly. Her eyes went wide, the flash of sudden fear too much.

"Oh my god, man, I love Phantom. Can you sing the song about the masquerade? It'd be so meta!"

"How about we leave it with a threat that if you touch her again, I will garrote you and leave your body in the rafters of the nearest theatre?" Mycroft stated coldly, freeing her from the stranger's wandering hands. "Scurry off, now."

The man quickly faded into the crowd.

Molly led Mycroft to the edge of the room. Neither felt like drinking with so many people pressing in around. They couldn't think with all the noise.

"Where would you go, if you could go anywhere on a day trip," Mycroft asked loudly at random, trying to make simple conversation. He expected her to hesitate while she thought, or debate between several options, but she had a prompt answer ready.

"Dover Castle," she said over the music, "I'm going in two weeks as a treat for the bank holiday. Saw a documentary on the restoration work there, looked fascinating. Want to come?"

"Barring international incident, certainly," he agreed. He checked his watch. It had only been seven minutes since their arrival and they had made an agreement to stay an hour. "Dover is less than two hours on the train. Were you planning on staying the night, or doing it all in a day?"

"Be easier to just come home, and maybe stay at mine that night. It's closer to the train station than yours."

"That sounds cosy," said a voice beside them. Tom had reappeared with a flat of cans of cider that he was offering around to his guests. "Do a lot of friendly sleepovers with Mycroft now, Moll?"

Molly was prepared to launch into a just leave it style speech, but Tom continued.

"Consolation prize for the brother, eh? Gotta get your jollies off with at least one Holmes? Do you make him wear a Sherlock mask and hump hi-" there was a thwack.

Tom fell to the floor, holding his jaw, tins of cider scattering around him. Mycroft adjusted his suit jacket with a hand that was likely to be aching soon. The hit had been fast, effective, minimal drama, and if Molly had any doubts of the range of Mycroft's previous legwork, it had been ample demonstration.

"That was terribly rude, Tom," Molly said acidly at the green man on the floor. "Mycroft is a dear friend, and there is no cause to be disrespectful to either of us. We're going."

They made their way to the door and out into the quiet of the dim corridor. He removed his mask and checked his watch. In and out in less than ten minutes, small mercy.

"I can't believe that neanderthal," she hissed. "That's so humiliating." Anger bristled off of her as she quick-stepped down the hall toward the stairs. While she walked she pulled a folded plastic bag out of a discreet pocket in her costume dress, open it up and handed it to him to hold. He deposited his mask inside. She pulled off her costume dress while they took the stairs down, a simple close-fitting modern dress underneath, and shoved the fancy gown in the bag.

They exited the building into the back alley. It was dark but for a single bulb overhead. She stopped him with a hand to his chest. Looking down at her, he saw that her expression was fierce, her eyes boring into his.

"Don't you ever, ever for a moment, think that I don't see you for exactly who you are. Don't you doubt for a moment how much I value what we have together."

Taken aback by her sober vehemence, he didn't know how to respond. He held up his hand, knuckles visibly swelling.

"Think I'd risk life and limb just to defend my own honour, my dear? I assure you, I'm far too domesticated for that sort of thing these days."

"Did you threaten to garrotte someone in there," she asked with a faint smile.

"Mostly domesticated," he corrected. "I'm not sorry to leave that ghastly collection of noise and people, but we do seem to have a great deal of time on our hands this evening now. Any preferences?" They made their way out to the street, and he called a cab.

"Bottle of wine and a good sulk," she sighed.

"Counter offer: decent take away, bottle of wine, and a quiet night at mine. I have a great deal of reading I need to catch up on for work, after the upsets of the past couple weeks. We could sit in the library in front of the fire and you could read, brood, sulk, whatever pleasure takes you, if it wouldn't be too boring."

She turned and gave him a gentle smile that made him feel strange inside.

"I can't think of anything better. Mind if we stop at mine on the way?"

They went to her flat, jettisoned the bag of costumes, and Molly quickly changed and packed up for the evening. In between staring matches with the cat, who was definitely standing on the cooker, he noticed that most of her overnight bag was already packed with extra this and that which only was used at his home.

"There's a blue ice pack in the freezer," she said, packing her tablet and charger into the bag on top of her clothes and picking up a professional looking folio and notebook. He tended his hand, and she disappeared into the bathroom to remove all the pins from her fancy hair. It came down in long loose curls, overly romantic against her comfortable jumper and jeans.

"Shall we?"

In the cab over, they debated over a place to order dinner. The pickier one (Mycroft obviously) winning. Molly made the order online on her mobile while they drove, Mycroft sat back against the car seat, looking out the window as they entered his neighbourhood.

This evening felt different, unsettling. In the past two hours they had made plans to go away together for a day, had defended the validity of their not-relationship, had a companionable evening planned with no mention of sex, and now he was wondering whether it would be practical to ask if Molly simply wanted to leave some of her things at his home. The idea of carving out any space for her felt like a violation of their spoken expectations. And yet she had given him a key to her flat with no expectation of its imminent return. He supposed that he had given her the combination to his back door her first time there, and not changed it after, but that didn't feel as real.

They arrived home, and the key became quickly relevant again.

"Is that my old keychain," Molly asked, peering into the priceless glass bowl where Mycroft was about to dump his pockets. "You've taken the key off of it," she observed.

"Yes," he tried to say casually, holding up the small ring he usually carried. As she had once said, there were very few locked doors in Britain for Mycroft, and he didn't have much need of keys. On the ring was the one for his front door, the master for all his non-swipe security lockups, and now hers. She gave him a wry look that he couldn't entirely understand, and a kiss on the cheek.

"I'm going to go put my things upstairs." She popped a couple of notes on the hall table from her purse. "My share of the food when it arrives."

"Dining room," he offered.

She shook her head, taking the stairs quickly.

"Please no, I can't sit at that table without hearing your mother say quim."

He wandered into the kitchen, and put the now-warm ice pack in his nearly-empty freezer. He selected a bottle of something that would go well with a dinner that was likely arriving in styrofoam, and a pair of glasses. Reading material he retrieved from his private office, someplace he was fairly certain Molly would have carefully avoided on her initial tour of the house, and he left it in a pile on a chair by the fire in the library. He was equally certain she would not be tempted to snoop. Very little of it was exciting reading. Lots of backgrounds, dossiers, non-urgent security briefings, policy drafts, international affairs, and a new autobiography in Spanish on an up-and-coming dictator he was watching closely.

She joined him with her notebook folio, tablet and charger, plugging it into a well hidden outlet added into the panelling of the room.

"All the journals I follow are pdf now," she explained. "Saves a great deal of office space."

It was near-silence for hours in the cosy little room as they concentrated on their tasks. At no point had Mycroft actually forgotten her presence, but found it was a pleasant accompaniment to the work. She didn't interrupt him when she came across something interesting, but made notes in her book. He answered a couple of calls from his office, but she waived him to stay seated, he wouldn't bother her.

He did notice Molly frowning at him once, when he needed a bathroom break and she caught him dog-earing the corner of the page of the book he was skimming.

"The whole book'll probably be in the office incinerator this time tomorrow," he confessed, dropping a kiss on her scandalized forehead before leaving.

"Defiler," she called after him.

At midnight, Molly admitted defeat.

"I think I've read this paragraph three times, and I'm not making head nor tails of it. I'm calling it for the night." She switched off her tablet, and put it and her notebook on the small antique desk. "Mind if I'm a bad guest and head to bed without you?"

"No, not at all, my dear. I'll be up in doscientas páginas. Please make yourself comfortable."

She stopped by his chair to give him a very warm kiss on the mouth.

"Let's have some fun in the morning," she said, leaving him with a playful nip under the jaw.

He sat in the heavy solitude of the room, flipping pages at his usual rapid pace, for around fifteen more minutes when there was a beep-beep-click from his back door.

"If tonight's the night you intended to strangle me in my sleep, Sherlock, you've come too early, I'm still awake," he drawled.