Hello, everyone! I'm not much one for Author's notes but I figure I ought to leave one in this case. This story started out intending to be a brief fill for a prompt on the sherlockbbc kinkmeme, but wound up into quite the mammoth of a project, not only due to my massive love for Sally/Lestrade or my penchant for AUs, but also because I tend to use writing as an escape mechanism, and I'm not only dealing with finals week but a very personal death in the family. Writing this has helped greatly to work my way through hardships, and I'm very thankful for the original poster of the prompt that inspired all this. I've really enjoyed writing this up, and do certainly hope that you all enjoy reading it just as much.

Before you read, I would like to leave a great heaping pile of thanks to my dear friend and beta reader burninganchors, whose work you should all go check out post-haste!

thank you all so much for your words of kindness and support!

The twenty-ninth of June, 1986, was one of the mildest and most pleasant days London had seen all the year long. The sun peeked cheerfully out from between fluffy white clouds, kissing the skin and casting shadows perfect for puppet theatre, if anyone was interested in that sort of thing. A gentle breeze played through the leaves on trees, catching tendrils of hair, just strong enough to alleviate the heat of the day. The city seemed almost alive with the joy of its citizens, breathing deep and encircling long contented arms around every one of them. It was a day made for picnics, for long walks through the park feeding ducks, for children to play.

It was on the twenty-ninth of June, 1986, that Martha Donovan turned her back for only a moment, and her daughter ceased to exist.

Sally Donovan had been four years old. Her favorite color was froggy green, and when she grew up she wanted to be a mattress. She doted on "her" dog, a chocolate lab named Pookie, and had two older brothers named Scott and Simon. Her mother was fond of the letter 'S'.

Other than the pleasantness of the weather, there was nothing extraordinary about the day on which little Sally disappeared. A day the week before, however, when Detective Inspector August Donovan apprehended no less than four out of five major players in a child smuggling ring, was quite extraordinary indeed.

August knew almost instantly what had happened to his youngest child when he'd been told of her disappearance. He immediately directed his teams into the search for the last smuggler, set up moles in the system to keep watch for a little girl in a froggy green jumper being sold on the black market. Knowing how important it was to find Sally - not just for their boss, but because finding her would clearly cut the path back to the smuggler - the detectives and constables threw themselves into the search with as much voracity as vultures on a carcass.

Months passed, and the flow of abducted children through the underbelly of society stopped altogether, without any sign of Sally Donovan. The cellar of an old house in Brixton, however, held a single tiny occupant. A year passed, and she was given up as dead. A small service was given at the local church, but half the Met showed up to show their solidarity with August. Any other man whose occupation had led to the loss of his youngest child would have retired and spent the rest of his days in misery, but August was not one of those men. He knew that if there was even the smallest chance of his Sally still being alive out there, it would be him who found her.

On the day of the funeral without a corpse, a cellar door was cracked open to shine a sliver of light down onto the dirty, drugged child lying in wait below.

Jefferson Hope smiled down at the little girl in the tattered remains of her green jumper.

"Come on out, Cindy. It's safe now."

The unwitting child crawled up the stairs at a snail's pace, wiping dust and tears from her cheek before reaching her arms out to be picked up, only to have a heavy plastic bracelet that blinked a little green light put around her wrist.

"There," said her new foster father. "Now, see this green light? If it turns red, I'll find you and feed you to a pack of dogs." He swatted her across the face and pushed her into a tiny side-bedroom that she would share with his two natural daughters, who were eight and ten. They ignored her sniffling and showed her the small nest of blankets on the floor that would be her bed for the rest of her natural life, bouncing on their own proper beds as they did so.

"Your name's Cindy Hope now," said the younger, purple letters above her bed spelling ALICE. "If you try to run away, Meghan and me will rip out your fingernails." She smiled beatifically.

"Meghan and I," muttered the other absently.

Sally - or Cindy, rather - sat quietly on her nest and stared at her hands. She missed her mummy. Did she have a mummy anymore?

A week later, Cindy was made to unlock the door of another cellar in the back garden. Inside was a girl a year older than her in a tattered pink party dress named Andrea.

From the very moment the tracking bracelet was snapped around her little wrist Andrea was trying to escape the house and facing the consequences. She was six years old, after all, and many six-year-olds believe themselves to be invincible as long as they believe hard enough. And little Andrea Hooper, well, she could believe her way right out of anything. Almost like clockwork once a month, the skinny little slip of a child found a way out of the locked-up house while Meghan and Alice were at school and Papa Jeff was working. She was tracked down within miles almost every time because of the tracking bracelets that were connected to Papa Jeff's watched, but their "stepfather" never brought his full punishment upon her. He didn't want his own daughters, who had become as attached to the young girls as they might to a pair of disgustingly endearing slugs, to be cross with him. Instead Andrea - renamed Marie - would be beaten and locked in the cellar for a week, or sometimes leashed to the roof of the house and made to sleep in the cold and rain for the night.

"Someday you an' me, we'll run away," Marie promised Cindy almost every moment they were alone together. Even though Cindy had been a prisoner in the house for months longer than her, Marie was older and took her role as surrogate big sister very seriously. She had had a little sister of her own back before her child's mind could remember, a wrinkly little worm named Molly. "We'll grow up big an' strong, an' then we'll tie up Alice an' Meghan an' make 'em eat dirt. Then we'll wait until Papa Jeff comes home from work an' lock him in his taxi an' put a brick on the go-pedal an' watch him drive away forever an' ever."

The girls giggled delightedly over whatever menial chores they were being forced to do, unable to contain the delight at imagining their stepfather driving away in a car going by itself.

Three years after being released from their months of captivity in the cellars, because they had been so very young and with underdeveloped limbic systems, it seemed that Cindy and Marie had almost completely forgotten about the families they had before Papa Jeff and Alice and Meghan. They knew that they had had Mummies and Daddies and there were very fuzzy recollections of siblings, but the faces and names blurred together in muddled confusion. Even their own natural names had faded ages ago, because of the sedating drugs Papa Jeff had kept them on during their time in the cellars. However, the loss of their identities, if anything, made the girls even more determined to someday escape the lives they were leading and find out where they truly belonged.

Despite being unable to go to school without funny questions being raised over their tracking bracelets and occasional battered faces, Cindy and Marie were able to learn how to read and write on their own. Every morning they would rush through their chores until the house was clean, then sneak into Papa Jeff's office and pore over his books with Alice and Meghan's old primary school workbooks they'd nicked from the rubbish bin.

Both girls were clever in their own ways as the months and years wore on. Marie was brilliant at Maths; she could solve any problem put in front of her within minutes and hardly any mistakes. Alice and Meghan usually made her do their schoolwork for them, and she didn't even mind. She loved it, the way the numbers and symbols all fit together so neatly like puzzle pieces. To her, numbers made sense in a life that did not. She could invent formulas for the perfect way to win any quarrel, and used them to her advantage often, even if it did earn her a slap in the face when she turned those powers on Papa Jeff.

Cindy, on the other hand, was gifted with the ability to hide in plain sight, and the art of lying. Or "storytelling," as Marie liked to put it, even though Cindy knew it was nothing so special (though once she did convince Marie that Papa Jeff was only keeping them until they were grown so he could eat them. That had been a funny afternoon). She was quieter than her foster sister, and much less rebellious. More frightened, really, because she saw the way Marie held herself for weeks after trying to run away like her ribs were sore. Cindy hated pain, never wanted anything to do with it. She knew the best places in the house to hide when Alice and Meghan were in the mood to "play," or when Papa Jeff was unhappy with her. She was smaller than Marie, and could fit into all the tiny crevices that no one ever thought about in their own homes. Not to mention she was black, which she was convinced helped her hide in the shadows, even though it really made no difference at all. Because of that, she saw and heard things that were never meant for her eyes and ears. All of it went to some deep-seated part of her memory, to be used when the timing was right.

As the girls grew older and more clever every day together, as the sensationalism behind computers and internet rose to heights unknown, Marie's interests shifted from the simplicity of numbers to the foreign land of programming. It was like learning a second language, and utterly thrilling. It was child's play to guess Alice and Meghan's password on the desktop computer, and soon the girls had abandoned their schoolwork hours early to learn of this new enigma. Especially when they grew up enough that their tracking bracelets could not be mistaken as bulky children's watches, and Papa Jeff moved them to the girls' ankles, being very careful to rotate them every few weeks to avoid rashes and infections.

"Couldn't we, I don't know, send an email to someone?" Cindy asked. "Couldn't they get us out of here?"

Marie shrugged. "Would anyone ever believe us?"

She had a point, really.

It was when Cindy was 17 and Marie 18 that everything changed. Convinced that she would be able to get the proper help, Marie slipped out the window with a promise to return for Cindy as soon as she had the means to do so. With the tracker going haywire the further away Marie ran - this time with more skill and determination than she'd ever had as a six year old - Papa Jeff threw Cindy down the basement stairs and locked her in before leaving to find the older girl. He was gone for four days searching, while Meghan and Alice neglected to either take Cindy out of the cellar or feed her. When Papa Jeff returned, without Marie, he took his anger and frustration out on Cindy. From then on she was locked in the cellar during the day while he was working and made to do her chores at night while everyone was sleeping, and if she woke anyone there would be trouble.

She wouldn't see her foster sister again for two years.

Some strange part of Cindy had somehow hoped that once she turned 18 she would become as brave as Marie, and find a way to escape as well. But her eighteenth year passed way into her nineteenth, and no revelations came. Instead she found recluse in her hiding places, and one night found it to pay off.

Papa Jeff was in the kitchen and Cindy was wedged under the stairs listening as someone came inside the house without knocking. Slow, steady footsteps moved around the hall until they came to rest in the kitchen where Papa Jeff was sitting at work.

"Evening, Jeff."

"Sir."

"Oh, you know it's not really me, Jeffy. Just a puppet. But I can hear you. And see you. Don't you worry about that, old sport."

"I...I won't, sir."

Cindy swallowed, not liking anything that could make Papa Jeff sound afraid.

"Do you know what's happening in a month, Jeff?"

"No, sir."

The sound of papers flopping onto the kitchen table.

"A benefit?"

"Yes, Jeff. Three days. For the families of children lost in your ring all those years ago. First day is a 5k marathon, second day a silent auction, and third day a ball. I do so love a good ball; the dresses burn so prettily."

"What do you want me to do?"

"You're a clever man, Jeff. I'm almost certain you can read. Your instructions are quite clear."

A brief silence as her stepfather read the files. "Botulinum? In the water?"

"Just so. Every competitor will be dead by nightfall."

"And...and Tsetse pupae in the artifacts?"

"The shipment will arrive the night before the benefit begins. They should hatch within two weeks. Buyers will be dead within a few days after that."

A cough. "Right. And the third a bomb, how very...well, messy, really. Why a bomb?"

"Call it a weakness of mine."

"Right. Alright. Why do you need me to do this?"

"Your daughters will be settled for life if you pull this off, Jeff. The crown prince is taking a very intimate interest in this benefit, and participating in every event. Kill him, and any grandchildren you may have will be set as well."

Papa Jeff swallowed thickly. "Right. And if I fail?"

"Let's hope you don't."

"R-right."

And then the man was gone. Papa Jeff leafed through the files for a bit longer before tucking them under his arm and going to bed. Cindy swallowed a lump in her throat, fighting cold shakes that had suddenly overwhelmed her in the space under the stairs. She knew that her stepfather was a horrible person, of course she did, but to murder hundreds of people without a second thought, just for money?

She had to tell someone, somehow, but it was impossible. Even if she could somehow email Scotland Yard about the threats, they probably got dozens of emails like that every day and would never take Alice's email address - preshypantslol69 - seriously, and hers was the only account that Cindy knew the password to anymore since Meghan actually made the effort to change hers once in a while.

Feeling utterly helpless and unable to control any bloody thing in her whole damn life, Cindy shuffled back into Meghan's bedroom (Alice was at uni and the elder had returned home to help in the family business) and settled down onto the paper-thin mattress she'd inherited from a skip. She and Marie had shared it for as long as they'd been together.

Too pent-up to sleep after almost an hour tossing and turning, Cindy got up and snuck outside with little fuss. She and Marie had figured out ages ago exactly how far their bracelets would allow them to venture without trouble. They could go a full three houses down before they went into the red, but when Marie had gotten it into her head to try going to one of the neighbors for help some sort of sensors attached to the gate set it off. Papa Jeff was always cleverer than they anticipated.

The cool night air cleared her head, and she was able to think again. How could she stop this from happening? What could she do while confined to this blasted stretch of road? She was completely helpless, and the crown prince Gregory was going to be killed because of it. Meghan had had a tabloid photo of the prince hanging on the bedroom wall for weeks until Papa Jeff's boss made it clear how he felt about the royal family. Then Meghan took it down, and Sally had scrounged it from the bin. She didn't know why, but there was just something in the prince's face, those deep brown eyes, that made her feel a little less alone in the great big world. She didn't want him to die, especially not when she had the information necessary to prevent it.

As she turned round to walk the length back to the house and repeat, Cindy's foot caught on a crack in the pavement and she tripped right over. Her bracelet chipped, and she froze as though somehow the minute damage would cause the whole thing to go haywire. When the green light didn't change she let out a sigh of relief. Papa Jeff was short enough with her since Marie had left, and Cindy didn't want the tantrum that would result if she needed a new bracelet.

Three weeks of the four passed while Cindy continued to worry about what she was going to do, for surely she had to do something. If she didn't, and all those people died, it would be just as bad as killing them herself. Then, one night as she lie awake fretting, a slip of paper sailed through the open window and landed right on Cindy's chest.

You can save them all. Be at the end house at midnight, the eve of the benefit.
Love,
Marie

A thrill shot through Cindy's chest. How...? Marie knew what was happening? Was she back at last? Leaping to her feet Cindy rushed to the window, ignoring the blind kick Meghan shot at her in her sleep to peer outside, but there was no one there. Choking down disappointment, she went back to bed.

There is no word in the English language to describe the apprehension Cindy felt as the days to the benefit dwindled. Then, on the very eve of the 5k, she finished with her chores, found something to eat that didn't need preparation, checked the kitchen clock about four dozen times, and ventured out into the night for the end house. Her skin was buzzing with the thought of seeing Marie again, so much so that when she saw the dark mass slowly approaching the boundary, the second figure went completely unnoticed as Cindy drank in the image of her foster sister for the first time in two years. Her hair was longer, darker, shinier and thicker with care, her face softer and curves more pronounced.

"Marie you look...amazing!" she gushed, choking on her own joy at the sight of her foster sister.

Marie smiled coolly, tight lines of tension around her eyes and mouth, then turned to the man at her side. Only then did Cindy notice the gangly young man with the big nose, garment bag, and umbrella. He nodded succinctly at Marie's inquiring look, and within moments the older woman's cool demeanor had fallen away and Cindy was being enveloped in her arms. "You have grown up so beautifully," she murmured into Cindy's hair with a muffled voice. "And I'm not Marie anymore, that wretched name he gave me. I go by Anthea now, and a dozen other names depending on the day." Marie - Anthea - stroked Cindy's curls and smiled beatifically.

"That's brilliant!" breathed Cindy happily, unable to believe her eyes even with all the evidence right there.

Then reluctantly, of course, she looked at the man who had granted Anthea permission to embrace her sister. He politely inclined his head toward her. "Mycroft Holmes," he said in way of greeting. "I am Anthea's employer. And I'm sorry, because wish as I do that we could secret you away this very moment, we need you to be our - as they say - inside man."

"Inside man?"

Mycroft Holmes swung his umbrella in a lazy arc, never once tearing his gaze from her. "You received your sister's note?" At her nod he continued. "You are capable of stopping these vicious attacks. From what my esteemed assistant tells me, you have a gift of observation. Use that and your cunning to your advantage, because I can only help you so far. This is your disguise for tomorrow afternoon; be sure to wear the sunglasses and cap." He handed over the garment bag without further ado - Cindy unzipped it to find sleek designer jogging gear - if such a thing even existed - inside.

Her eyes darted between Mycroft Holmes and her foster sister, who had reigned back in her aloof demeanor. "There's just one problem," apologized Cindy, tugging up her trouser leg to bare her ankle and its blinking bracelet. There was no way she would get away long enough to-

With another nod from her employer, Anthea stepped forward and pulled a small clamp-looking device from her handbag. She closed its jaws over Cindy's bracelet and hit the small switch. It briefly buzzed, and when Anthea pulled the device away the lights had gone out on her bracelet.

"It only lasts for around sixteen hours, give or take," explained Anthea apologetically. "The marathon is in the morning, so you should have plenty of time."

"But what exactly am I doing?" asked Cindy, feeling slow and useless. Some inside man she was.

Holmes smiled in a perfect imitation of sympathy. "We need you to firstly prevent the attack, then find the mole in the system; whoever has been leaking private government information will be present to admire their handiwork."

Blinking dazedly, different thoughts chased their way through Cindy's head. "But...I don't understand. If you know about the attacks, why can't you do anything about them?"

That seemed to have hit a nerve, but Cindy could only tell because she'd had practice with her foster family. "There's a specialist of sorts working the case," he grimaced mildly, "however, it would be in everyone's interest if the conflict was stopped before he can access anything vital. He tends to take a more destructive route in his investigations."

He may as well have said, "Cindy, you're our only hope," for the way it shook her very core. She nodded, not trusting her own voice. Holmes seemed to understand.

"Good luck, Sally," he said gravely, and then he and Marie - Anthea - were gone, leaving her to blink confusedly in their wake.

Who was Sally?