AN: Research papers are horrid, and I needed a break, and I've been thinking about this all day long ever since I posted this idea to my blog. Well, obviously I beefed it up a bit more because this idea is freaking adorable. This is my first Sherlock fanfic, so please, I'm begging you to leave reviews! I'll be back once this semester is over, lovelies. :)

Mycroft awoke that morning with smile. He was finally thirteen-years-old, and he couldn't wait to go to the cinemas with a few acquaintances to celebrate. Mummy and Daddy were away for the week on a cruise, but they had called to tell him happy birthday. He got up to begin his day, making sure to quietly walk past his little brother's room. It was early enough that he may still have a chance to sneak out without him knowing. He padded quietly down the hallway, already showered and dressed, and he rounded the corner into the kitchen, only to run right into his brother who was sitting at the counter with a smile on his face.

"Good morning, My! Happy birthday," Sherlock giggled.

Mycroft sighed softly, kicking himself for actually believing that the six-year-old would still be in bed. "Good morning, Sherlock. Thank you very much." He smiled slightly at the boy, quickly making himself some breakfast.

"Can we play together today? I want to play scientist, My," Sherlock begged.

"Perhaps later. I'm going out today," Mycroft replied, slathering jam on his toast. He didn't bother to look up, therefore missing the hurt expression on the child's face. "Listen, Sherlock. I don't know when I will be home, so I need you to behave. It'll just be you and nanny here for dinner tonight."

Sherlock frowned, "I don't like her, My. She's boring."

Mycroft rolled his eyes, "You'll just have to deal with it, Sherlock." He finished his breakfast, drinking the last of his tea before standing. "I'll see you later, okay," he asked as he put on his jacket. Sherlock looked down, nodding slowly, hiding his face. He quickly got up and ran to his room, slamming the door. Mycroft considered chasing after him, but he feared he would only make matters worse.

Mycroft was out with friends, and Sherlock alone with the nanny. After he had run to his room, he had curled up and cried in frustration, not wanting Mycroft to see him acting like such a baby. Ever since the teen had hit his growth spurt, he had begun to distance himself from his little brother, and Sherlock missed him desperately. After he knew that his brother was gone, he wiped his eyes and tiptoed down to his room, slipping inside and going to the bookshelf. He grabbed a book, taking it and plopping down on the floor to read it with interest. Mycroft didn't know, but this was his daily routine, and he would almost always finish the book long before his brother came home. Today's pick was To Kill a Mockingbird, and he was quickly scanning the lines with almost no difficulty. He had no sooner closed the book when he heard Nanny calling for him, so he quickly put the book back in the same spot he found it, knowing that his brother would notice if he didn't. He snuck out into the hall, "I'm right here, Nanny."

The woman turned to him, "Sherlock! I've been looking everywhere for you! Where have you been?"

The young boy rolled his eyes, "I'm here now, so what does that matter?" He walked past her into the kitchen. "I am starving. If you could make me something to prevent that, it would be splendid." He spun around on his heel, striding into his room, leaving her to make him food. He fell backward onto his bed, thinking of ways to get into trouble. A knock sounded at his door, and he got up to retrieve the tray before quickly slamming the door in her face. He ate his lunch, brooding quietly and humming his displeasure. He sighed to himself, knowing that he hated everyone but Mycroft. His older brother was always giving Sherlock ways to expand his mind. The moments he got to spend with his big brother these days were few and far between, but he treasured them, stored them for when he got lonely. The little boy closed his eyes, entering his mind palace with a smile. Mycroft had taught him how to start his, and he replayed the memory.

"My, how do you manage to remember everything," Sherlock asked one afternoon as he sat on his brother's bed, playing with his pirate ship.

Mycroft turned in his desk chair to face his little brother with a big smile. "Have you ever seen a picture of a palace, Sherlock?" The 4 year old nodded vigorously, his shaggy curls bouncing with enthusiasm.

"Yes, I looked them up in one of your encyclopedias last year," he smiled, proud of himself. Mycroft wheeled closer to the bed in his chair, clasping his hands together and resting his chin on them.

"Wonderful. Can you picture one, right now in your mind? Can you see how vast the space is?" He watched as the boy closed his eyes, concentrating hard.

"Of course I can, My," he huffed, offended by his brother's doubts.

"Now, I want you to think of your favorite place in the whole world, Sherlock. You don't have to tell me where that is, but just picture it," Mycroft continued, watching his brilliant little brother follow all of his instructions. "Any time you would like to store something for the future, simply deposit it there. Whatever catches your interest, whatever you feel is important, just place it in that location, almost as if you were decorating it to make it better for you."

Sherlock cocked his head, eyes still closed, "So what you're saying is that it's like a mind palace?"

Mycroft grinned, "Yes, that is exactly what I am saying."

Sherlock opened his eyes, "So, the memories I store there... They're like my buried treasure?"

"That's exactly what they are, little one, and don't let anyone take your treasures from you," Mycroft laughed, ruffling the boy's hair and making him smile. "Now, would you like to assist me with an experiment?"

Sherlock immediately jumped up, dropping his pirate ship to the floor, as he jumped up and down excitedly, "Oh, please, My! Can I, please? I love experiments!"

Mycroft grabbed him by his shoulders, laughing at the enthusiasm of the four-year-old, "Easy there, Sher! You're going to break your ship. Of course you can help me. Meet me in the gardens in ten minutes, okay? Bring your rubber boots!"

Sherlock rolled onto his side, thinking about what his brother might be doing. Suddenly, he sat up, a smile spreading across his face as he realized exactly what he could do to both cure his boredom AND involve his brother. He wanted him to have a nice birthday, and since their parents weren't there to celebrate with him, he knew exactly what he was going to do. He was going to bake a cake.

Twenty minutes later, Sherlock stood on a stool in the kitchen with the necessary ingredients set out before him. He began to mix things together, confident that it would come out fine in the end. Once he felt he mixed enough, he poured it into a pan, then stuck it in the oven. He turned the temperature dial all the way up as to make it finish faster, but he had some time to kill. As he passed by the sitting room, he smiled at Nanny, glad to see she showed no signs of stirring after he had slipped that sleeping pill into her tea. She shouldn't be a problem for awhile, he thought happily. He continued back to Mycroft's room, grabbing another book off of the shelf to pass the time. As he dove into Of Mice and Men, he became too interested, and forgot all about the cake. Suddenly, the smell of smoke invaded his senses and he set the book aside, running quickly to the kitchen. The he opened the oven door quickly, seeing that his cake was on fire. He reached for the potholders, trying to grab it out, but one of them caught fire almost instantly. As it burned his hand, he instinctively let go of it, and his eyes widened in horror as the flames spread further. Sherlock scanned the counter, immediately realizing that he had accidentally knocked over the bottle of vegetable oil, and he began looking for a way to put out the fire. He finally gave up and slumped down the wall across from the fire, tears pouring down his face as he whimpered for his brother.

The cinema had suffered some technical difficulties, and so the night had been cut a bit shorter than he had expected. Mycroft took his place in the cab, thinking that maybe he could dive into one of his books and salvage the evening. Before he knew it, the cab had stopped at the estate, and he paid the cabbie before making his way inside. As he opened the front door, his senses screamed in danger as the smoke filled his nostrils. Sherlock. He lunged forward, following the smoke trail. As he turned into the kitchen, he immediately sprang into action, recalling everything that he knew about fire control. He retrieved the fire extinguisher, and a few minutes later, he had the fire out. He gasped, taking deep breaths and wiping his forehead, relieved. The sound of his brother's sobs rang through his ears, and he found him crouching up against the wall, shaking. He hurried to him, dropping to his knees to check the boy for any damage. "Jesus, Sherlock! Are you alright? What were you doing? Where is Nanny," he demanded, putting his hands on the six-year-old's shoulders.

Sherlock looked up at him sadly, tears streaming down his face, "Don't be mad, My! Please, I didn't mean to! I wanted you to have a nice birthday!"

Mycroft looked at Sherlock, sighing softly, "My birthday? What does that have to do with this, Sherlock?" The boy pointed to the open oven door, and Mycroft went to investigate, seeing a badly charred cake.

Sherlock stood and slowly came up beside his brother, his lip quivering, "I'm sorry, My. Please don't be mad, please."

Mycroft sighed and looked down at his little brother, ruffling his hair, "Oh, Sherlock. How could I be mad at you after you went through all this trouble to make me my favorite?"

He smiled down at the younger boy, and Sherlock hugged him, "Happy birthday, My." Mycroft hugged his brother, continuing to softly ruffle his hair to calm him down, wondering exactly what their parents would say when they saw the damage, but he didn't care. He was touched by his little brother's attempt to make him a cake. He hadn't a homemade cake in years, and he tightened his hold on the emotional little boy. It definitely wasn't the night he had been expecting, but oddly, he felt better about his day now that he put everything behind him. "Sher? Would you like to come spend some time with me? I'll read to you if you want, just like I used to."

Sherlock looked up at him with a genuine smile, "I've missed you, My." He hugged his brother once more before splitting away. "Will you read me a mystery?"

"Of course I will, Sherlock," he chuckled, ruffling his hair once again. His smile faded as he realized something was missing. "Where is Nanny? You never answered me." Suddenly, a groan sounded from the living room, and he couldn't help but smile as he listened to her slowly coming to. She was going to faint again when she saw this mess, and he just did not care. "C'mon, let's go."

"Hey, My! Do you think Mummy and Daddy will let us get a puppy," Sherlock asked excitedly as they entered the boy's room.

"I'm sure they could be persuaded if you use those marvelous manipulation skills of yours, brother dear," he chuckled.

"I learned from the best, My," Sherlock grinned.

Mycroft rolled his eyes, "Yes, now get into your dressing gown, and I'll be right back with a book, alright?" He closed the door, going into his own room and flipping on the light. He froze, his eyes narrowing as he noticed the book on his floor. He made his way over and picked it up, smiling as he read the cover. Sherlock. Clasping it gently in his hands, he slowly walked to his bookshelf, he grinned to himself. He thought he had noticed his books to be a tad bit off-center to the pristine way he usually had them in, and so he took a moment to appreciate his brother's thirst for knowledge. Mycroft had been too busy worrying about his schoolwork and everything else that he hadn't fully realized how much he had been neglecting the poor boy lately, and his heart squeezed in guilt. As he made his way back to Sherlock's room, he decided that he would convince his parents to let Sherlock have a puppy to keep him company when he couldn't. A friend for the boy that would be loyal to him always, and more importantly, protect him, for the loss of his brother would truly break his heart.