Spoilers: Assumes knowledge of the most current seasons of both shows.
Disclaimer: I own neither Sherlock nor Doctor Who; all rights belong to their respective owners.
Thank you to my wonderful Betas, susako and infinityuphigh, for all their help. All remaining mistakes and inconsistencies are my own.
Laying The Foundation:
Mycroft sat stretched out on the window seat of the third story flat, thoroughly engrossed in a book about the Ancient Egyptians when his vision was suddenly blocked by a mound of dark curls brushing against his face.
"What are you reading?" asked the young Sherlock, who was now leaning uncomfortably against his brother's chest.
Mycroft pushed Sherlock aside and said, "It's about the mummification process. Now go away."
"Read it to me," said Sherlock, more of a demand than a request.
"No," replied Mycroft. "This book isn't for six year olds."
"Why not?" Sherlock pouted.
"Because," stated Mycroft.
"But I want you to," Sherlock said, starting to whimper a little bit.
"Mummy!" Mycroft shouted across the living room. "Sherlock's bothering me."
A few moments later, Mummy came into the room from the study to see what all the commotion was. "Mycroft, be nice to your brother."
"But I'm trying to read," explained Mycroft, annoyed at being scolded just for being older, "and he keeps interrupting me."
Mummy sighed and reached her hands out to Sherlock, saying, "Come here, Sweetie."
Sherlock frowned at Mycroft, then ran to his mother's arms, which wrapped around him into a big hug. "Let's leave Mycroft alone for a bit, shall we?"
"Tell me a story, Mummy," Sherlock said.
"Alright," she said, brushing back some of the long curls from his forehead. "Which would you like to hear?"
"One about you and Daddy in the blue box!" he answered rather quickly.
Mummy smiled and scooped Sherlock up so that she could reposition herself on the nearby armchair, placing her son in her lap.
"Well," she began. "As you know, once upon a time, Daddy and I met a mysterious old man who owned a blue box. But this wasn't just any ordinary box. This box could do all sorts of seemingly impossible things. It was called 'The TARDIS', and it could travel in both time and space to wherever you wanted to go.
"On one of our adventures with the Doctor," she continued, "Daddy and I, and the Doctor, and a girl we had met named Vicki landed in a very large and very strange museum on a far away planet, and it was filled with mementos of hundreds of different alien races from all over the galaxy. But do you know what the strangest part of it was?"
"What?" asked Sherlock, eyes wide in anticipation. At this point, even Mycroft, who, at the very mature age of thirteen, was purportedly much too old for such fairy stories, had given up all pretense of reading his book in order to listen instead to his mother's tale.
"We all saw our own future selves on display as one of the exhibits. And this made us all very concerned. We then had to figure out a way to prevent whatever events would place us there from happening..." Sherlock listened intently as his mother told her story, snuggling as close as he could into her embrace, feeling the constant thump of her heartbeat against his cheek.
Afterwards, Sherlock went in search of some paper and crayons. By the time Daddy had come home, Sherlock ran up to him brandishing one of the pictures he had drawn.
"What's this?" asked Daddy, bending down to better inspect the drawing.
"It's you and Mummy and Vicki and the Doctor looking at yourselves in the museum," explained Sherlock. "See, that's you."
"And I think you've captured my essence wonderfully," Daddy said.
Pleased with himself, Sherlock ran away to his bedroom to play with his toys. If he had stayed, he would have witnessed his father walk up to his mother to have another talk about all the stories she was telling the children. It could be dangerous if the children passed them on– people might start asking questions again, or, worse, they most probably would not believe the stories and with one slip-up, Sherlock would be made to look foolish in public, becoming the subject of schoolyard taunts. Mycroft had become skeptical as he aged, believing them only to be made-up stories, but Sherlock was of a much more whimsical disposition than his older brother. Mummy agreed that she should have a talk with their son later tonight, but was very sorry to have to ruin his fun.
"Round and round the garden like a teddy bear," Mummy sang, gently tracing her index finger in a circle around Sherlock's right palm. "One step, two step," she continued while walking her fingers up Sherlock's arm. "Tickle you under there!" she finished by tickling him on his tummy, while Sherlock laughed at the onslaught of familiar touches.
Mummy then kissed Sherlock's forehead as the last few stray giggles escaped his mouth, and then she tucked him in under the duvet.
"Sherlock," she said, in a much more serious tone than just moments ago.
"Yes, Mummy?" said Sherlock.
"There's something very important that I need you to do for me," she told him. "I need you to keep a promise. Do you think you can?"
Sherlock nodded his head, but remained silent.
"All of those stories that Daddy and I have told you about the Doctor and his time machine have to remain a secret," she declared. "You must not repeat them to anyone except Daddy and me or Mycroft. Can you do that for me?"
"But why, Mummy?" he asked, the distress apparent in his voice.
"Because many people just won't understand," she explained. "Even when Daddy and I first stepped into the TARDIS and saw with our very own eyes, we just didn't want to believe. And so others, who won't ever even get a chance to see, will say you're telling lies, and there won't be anything you can do to change their minds."
"But what if I help them to see?" asked Sherlock.
"I'm afraid you can't, dear," said Mummy.
Sherlock frowned for a moment before asking, "But he is real, isn't he?"
"Oh, yes, he is," she said. "I promise you that. Now, will you promise me?"
"Yes, Mummy," replied Sherlock, who then shifted onto his side and curled up in his bed.
"Goodnight, Sweetie," she said, kissing her son on his temple.
"G'night, Mummy," said Sherlock.
Sherlock had been standing by the sofa, practicing his violin, while his mother prepared dinner in the kitchen. She listened carefully to the music, humming along to the tune. When the doorbell rang, she walked over to the door and opened it to reveal a man who she had never seen before.
Sherlock instantly stopped playing, and peered in their direction, catching a glimpse of the stranger standing in the threshold. He was of average height, worked out on a regular basis, owned a large dog and was unmarried, though he had a girlfriend.
"Can I help you?" his mother questioned.
"Are you Mrs. Barbara Chesterton?" he asked.
Sherlock noticed his mother become rigid. "No," she told him. "I think you've come to the wrong place. My name is Barbara Holmes. Good day." She then began to close the door on him, but he stuck out his foot to block the action.
"Look," he said. "I know, I get it. You don't know me. But I know who you are, and I just want to hear the story. I'm a writer; and if we sell your mystery, you'll be set for life." He turned to look at Sherlock. "You can give your kid everything he'll ever need."
Sherlock was quickly aware that this man didn't know his mother because if he had, he would know never to make her angry. And she was very angry. Sherlock braced himself; he always did enjoy hearing why other people were wrong.
"Now see here!" expressed Barbara. "I don't know who you think you are, but if I ever see you on my property again- no, if I ever see you near myself or my family, I will call the police for harassment."
"Wait," he said, holding his hands out to plead with her. "I didn't mean-"
"Oh, you didn't?" she retorted, raising her brow at him. "Now, I suggest you turn around, walk down those stairs, and disappear as quickly as you can."
"Okay," he said. "But if you ever change-"
She slammed the door in his face, then brushed her hands together with a self-satisfied nod.
"Mummy?" asked Sherlock.
"Oh," she said, turning to her son. "I'm sorry you had to see that, Sweetie."
"What did the man want?" he asked.
"Well," she said, coming over to the sofa and beckoning Sherlock to sit next to her. "He wanted me to tell him a secret, but I wouldn't tell him."
"Would you tell me?" asked Sherlock.
Barbara smiled at him. "I already have, Sherlock."
"About the Doctor and the TARDIS," she explained. "Do you remember a long while ago when I asked you to keep that promise about him?"
"Yes," Sherlock nodded. "And I have."
"Good," she told him.
"But that man claimed he knew about us," he said. "Why couldn't we tell him?"
"Because if we let him know," said Barbara. "He would tell others, and then our lives would become very complicated."
"Why?" asked Sherlock.
She sighed. "Because everything's complicated when the Doctor's involved."
"Oh," said Sherlock, though he still didn't understand. But the look in his mother's eyes told him everything he needed to know.
Sherlock ran to his room and slammed the door, falling onto his bed and punching his pillow repeatedly. Thrashing the pillow did help to calm him down a bit, and so he eventually ended up lying on his back spread-eagle, staring at the blank canvas on the ceiling above him. His bottom lip was cut, his knuckles were scratched, and his body ached all over.
There was a sudden knock at his door. "Leave me alone," he said in a voice that had already started to crack, signifying the bridge from adolescence to adulthood.
"Are you all right?" his mother asked from the other side of the door. "Did something happen in school today?"
"I'm fine," he replied.
She sighed audibly and then said, "I do worry about you, Sherlock. I know how cruel children can be."
Sherlock groaned and propped himself up on his elbows. "You can come in then, if you want."
Mummy carefully opened the door and gasped when she saw her son's scowling face. "Sherlock! What happened?" she asked, rushing over to his side to inspect him more closely.
"Some of my classmates surprised me after school let out," he said. "But they left looking worse than I do," he added with a smirk.
"Sherlock..." she began, but then thought better of it, and instead told him, "Get up, then. Let's have you cleaned up." She helped him down the hall and over to the bathroom and held her tongue upon noticing the slight limp to his walk.
"What are we going to do with you, Sweetie?" she asked as she found the bottle of antiseptic while Sherlock sat waiting on the toilet lid.
"You could homeschool me," he offered.
"We've discussed this before," she said. "You need to socialize with children your own age."
"But they hate me," Sherlock declared. "And I hate them. And anyway, the teachers at school are idiots; I can't fathom how you can stand to consider any of them your colleagues."
Mummy raised her eyebrow at him, but instead of starting a well-worn lecture about the value of teachers, she just poured a bit of the antiseptic onto an old flannel and touched it to the cuts and scrapes on Sherlock's face. Sherlock winced, but he too said nothing, creating a tense silence between them.
"Do you remember those stories I used to tell you about a girl named Susan Foreman?" Mummy suddenly asked.
Sherlock furrowed his brows. "Yes," he said suspiciously. "The Doctor's granddaughter. Why?"
"Susan was a student in my history class, and she also attended your Dad's science class," she said. "She was a mystery, that girl. In some areas, she was so bright, an absolute genius far beyond our understanding of the world; and in other places, it was as though she knew nothing of basic human sense and behavior."
"But why should she care," asked Sherlock, rolling up his sleeves to reveal more bruising, "if she was so much more extraordinary than everyone else?"
"Nonetheless," said Mummy, "she did care. She wanted desperately to fit in, to belong somewhere. It took her a while, but she finally managed to find a place where she felt at home."
"So what you're trying to tell me is to be patient?" Sherlock suggested.
"What I'm trying to tell you, Sherlock," she said. "Is that you're not alone in the way you feel, but you'll move on and you'll figure things out eventually."
"And what if I don't?" asked Sherlock, rolling his sleeves back down.
"A smart boy like you?" Mummy smiled. "Of course you will."
"If I'm patient..." Sherlock added.
"If you're patient."