Disclaimer: I do not own any of the characters of Arthur Conan Doyle, nor any of the various dramatic incarnations thereof. No profit is being made from this work.

Note: Welcome to this story! I had a lot of fun with my first Sherlock story, so here's another one.

The villains are inspired by real-life criminals. They're definitely bad people, and they do bad things to people, inflicting abuse both intentional and unintentional. I can't promise that characters won't get hurt. If you feel like you want to stop reading and read something else, I won't be offended.

That being said, enjoy the story, and I'll meet you at the end.

1. My Brother's Keeper

The crisp winter air burned bracingly in John's throat as he jogged steadily past the Royal College of Physicians. He had been on day shifts at the Princess Grace Hospital for the past week. The atmosphere there was pleasant, and it was almost obscenely convenient both to his home and to his daily jog around the Outer Circle of Regents Park. He had even enjoyed shifting the jog from early morning to late afternoon, because he could see new faces along the familiar route. Instead of the dog walkers and tai chi classes, John could watch old men taking their constitutionals and small children playing under the watchful eyes of mothers or nannies.

As he jogged down Park Square East, he had to skip aside to avoid tripping over a bright green ball that rolled across his path. The ball was followed in short order by a small boy, barely more than a toddler, in such hot pursuit of his toy that his surroundings made no impression on him whatsoever.

"Whoa there!" John reached down and scooped the boy into his arms just before he could follow the ball off the kerb and into the traffic of Euston Road.

"Georgie!"

A young woman in a worn blue hoodie barrelled out of the gardens towards them. John smiled and turned the boy toward her. "Lose something?"

"Georgie!" the woman cried again. She lifted him from John's arms and hugged him tightly. "Oh, Georgie, you could have been killed, you horrible child," and she showered kisses over his face. "What would your mum have done then? If it weren't for this nice man here . . ."

She glanced at John, and a broad smile lit her face, though her brow was still furrowed with worry. "Thank you," she said, blinking back tears. Her eyes were a marvellous shade of green.

"Not at all. Glad I was able to catch him in time, Miss . . .?"

"Dee," the woman said, glancing away. "Just Dee."

"Dee," John repeated. "Mmm. Lovely. Short for Deanna?"

"No. Just Dee."

"Ah. Well, pleasure to meet you, Just Dee. I'm John Watson."

"Thank you," Dee repeated. "I should go. Got to get him home for tea. We're not usually out at this hour. He must have gotten overexcited."

John smiled. "He'll sleep well tonight, then. Nice to run into you, Georgie. Stay away from the road till you're a bit bigger, alright?" John wiggled his nose at Georgie to make Dee laugh, then nodded to her and continued his jog down Euston Road toward Baker Street.

When he arrived at home, he took a few minutes to stretch before letting himself in. The post had arrived, and Mrs. Hudson had sorted it and left John and Sherlock's stack on a small table in the hall. John scooped it up without looking at it and headed upstairs.

He found Sherlock in the kitchen, peering intently into the new microscope that had been his Christmas gift from Mycroft. Sherlock did not look up when John arrived, but held out his hand. "Paper."

"What?"

"Paper. A small piece of paper. Give me one."

"Oh. Well, I've got the post." John rifled through it quickly to make sure that there were no bills for Sherlock to destroy. There were two catalogues, four magazine subscription offers, and a large envelope of silky, cream-coloured paper hand-addressed to Mr. Sherlock Holmes. John handed the whole pile to Sherlock. "You've got a letter there, so be careful. Have fun. I'm going to take a shower."

"Mmm."

John chuckled and went up the next flight of stairs to the bathroom.

The hot water loosened muscles that had just begun to stiffen, and John hummed a little as he towelled himself off and pulled on jeans and an old, soft jumper. Still finger-combing his hair into place, he returned downstairs to find Sherlock curled in his armchair glaring at the now-shredded cream envelope as if he had developed a personal vendetta against it. Which, John, considered, was not outside the realm of possibility.

"So, what have you got there?" John asked, making sure to keep his tone light.

"An invitation," Sherlock said. "I've been summoned to a soirée."

John could not stifle his laugh. "Sorry," he said. "I must still have a bit of water in my ears. For a moment, I thought I'd heard the word 'soirée' come out of your mouth."

"Oh, don't play games, John. You heard me perfectly well."

"Yeah, but it just sounds so . . . I mean, who actually uses the word 'soirée' to describe a drinks party these days?"

Sherlock's eyes narrowed even further. "The same sort of people who describe themselves as their younger brother's archenemy."

"Ah." John wondered if he should press for more details, but Sherlock beat him to the decision.

"Mycroft requests the pleasure of my company on Saturday evening for a formal reception at Number 10, with dinner to follow," Sherlock said, sounding as if he'd been invited to bludgeon a puppy to death.

John sucked in a breath. "Number 10?" he asked. "The Number 10?"

"What other Number 10 would Mycroft deign to use?" Sherlock said, his voice dripping venom. "I'm even allowed to bring a plus-one."

John was not an especially prescient man, but he thought he could see what was coming, and he wracked his brain for anyone who could present a plausible alternative. "Well, I'll bet that Molly's got something gorgeous in her wardrobe just waiting to be paraded in front of the Prime Minister."

"What? Why would I take Molly? It'll be dull enough there without her simpering at me."

"Mrs. Hudson, then? She'd love an evening out like that with you. Be a real treat for her."

To his credit, Sherlock did not immediately dismiss the suggestion out of hand. "She would. But, unfortunately, I'll have to leave her to her knitting, or whatever it is she does in the evenings. A plus-one invitation from Mycroft can only mean one thing." He stared pointedly at John.

"What, me? Seriously? No. Why me?"

Sherlock sighed. "Oh, keep up, John. It's Mycroft. 'Plus-one' sounds so much more elegant than 'handler.'"

John knew he was beaten, but it would never be said that Dr John Watson went down without a fight. It might be one of the most inane clichés ever used, but then, he'd gritted his teeth through "Where am I?" upon waking up in a field hospital with a bullet hole in his shoulder. He could do this. "What," he asked crisply, "do you think I'm going to wear?"

Sherlock waved the question away. "Surely you have something."

"I have a sports coat, Sherlock. You've seen it."

"What, that awful purplish-brown thing? You can't wear that."

"I know."

"I would send you to my tailor, but it's too late to have anything made. Mycroft should have thought of that."

John nodded. "You're right. But that doesn't get us any closer to solving the problem."

Sherlock looked John up and down as he considered the question. "Well, what did you wear to Harry's wedding?"

"Dress uniform. Can't wear that any more." But the mention of Harry's wedding sparked an idea.

Clara had dreamed of a traditional white wedding since she had been a little girl, and had not let marrying Harriet Watson put a dent in that ideal. She had worn a flowing, strapless white dress with a lace veil, and had suggested a graceful black pantsuit for her bride. But Harry had wanted something a bit more dashing, and she'd still had the figure to pull it off back then. "Harry was into Marlene Dietrich at the time," John mused.

"Who?"

"Old German film star, used to wear men's suits. Harry went to one of those formal wear shops and hired a dinner suit and top hat. Looked fantastic on her."

"Ah," Sherlock said with a crisp nod. "Well, then, there you are. Go back to that shop and hire a suit. Any shop that can fit your sister can certainly fit you well enough. There, that's settled." He unfolded himself from the chair, took the invitation to the mantel, and pinned it down with a decisive stab of Swiss Army knife.

John admitted defeat and went to find his mobile to call Harry and ask the name of the shop.

"I look like a headwaiter."

John stared at his reflection in the mirror and attempted to adjust his tie. He had never liked bow ties. Behind him, Sherlock crouched down to buckle John's cummerbund.

"At one of those really posh restaurants," John went on. "The ones with linen tablecloths and three sets of forks laid out on the table."

"Well, you're not finished yet." Sherlock finished with the cummerbund and picked up the dinner jacket, neatly laid out on John's bed. "Arms."

He helped John into the jacket, and then came around to the front to smooth the shoulders and perk up the white cotton pocket square. With deft fingers, he straightened the line of military decorations that John had pinned across the lapel. Then he stepped back so that John could view himself in the mirror.

John nodded approvingly at his own image. He couldn't hope to match Sherlock's bespoke, waistcoated elegance, but he fancied that the smooth dark lines of his own suit took five years off his age.

"You don't look like a headwaiter now," Sherlock observed.

"No, I don't."

"In fact, I'd say you've advanced all the way to maître d'hôtel."

John laughed. "Hush, you. Let's go out and hob with the nobs."

John was glad, but not at all surprised to find a shiny black car waiting for them out front. He was under no illusion that Mycroft had sent it out of politeness; most likely, it was there to ensure that Sherlock actually showed up at the soirée. Still, John appreciated not having to flag down a taxi and fumble with his wallet, which was lodged in an unfamiliar pocket.

Waiting for them inside the car was Mycroft's assistant, whom John still thought of as "Anthea," for lack of any other name. She wore her usual neat but nondescript business suit.

"Evening," John said as he and Sherlock settled themselves in the car. "You're not coming to the party?"

"No," she replied. "I'm to get you ready."

John cast a puzzled frown at himself and Sherlock, already dressed in impeccable style, as far as he could tell. Mycroft's assistant gave a polite little smile clearly intended to project affectionate tolerance of John's astounding idiocy. Quick as a flash, she reached out and whipped the pocket square out of John's breast pocket. John had time only for a choked "Oi! What are you -" before she replaced it with a much nicer handkerchief of white silk.

John fingered the silk, able to deduce only that it felt expensive, and then gave a grudging nod. "All right," he said, "but I'll need that one back. Belongs to the shop."

Mycroft's assistant gave another tolerant little smile, and turned her attention to Sherlock. She reached into a plain paper bag on the seat beside her and pulled out a plastic clamshell container that held a white carnation boutonnière. Two green leaves poked up in the back, and the main flower was augmented with a spray of baby's breath. Sherlock eyed the thing with open distaste, but allowed Mycroft's assistant to pin it to his lapel anyway. When she had finished, Sherlock glanced from his own lapel to John's more colourfully decorated one.

"I have never had any desire to enter military service," he began, and John sent silent thanks to the heavens for that, "but I am beginning to regret turning down those knighthoods."

"Bad luck for you, then," John replied, leaning back in the comfortable leather seat. "Maybe you'll remember that flower the next time that Mycroft tries to offer you one."

That earned him a glower and a snort. Satisfied, John gazed out the tinted window and began to allow himself to enjoy the novelty of attending a formal gathering at the home of the Prime Minister.