John Watson walked side by side with his friend as they made their way down the street towards his house. "So, how's it going with that project of yours?" he asked, trying to strike up conversation.
Sherlock simply shrugged. "Boring. Easy. Really only doing it 'cause I'm bored," was his answer.
"Ah. Well," John took a step onto the walkway that led to his house. "We'll find a way to make you not bored."
"Sherlock," a voice from behind them said suddenly.
Sherlock looked up, startled, and turned. The stranger gestured for Sherlock to go over to him. "John, go inside. I'll be there in a minute," Sherlock said.
John hesitated, but obeyed his friend's request. "I'll, uh... get some popcorn or something..." he said, turning and walking through the door.
When he was inside, he stood by the front window and watched the two outside. "Hello, John. Is Sherlock here?" his mom asked from the kitchen.
"Yeah," John answered absent-mindedly.
He focused his attention back outside. The stranger said something, and Sherlock gave him a look of dismay. Sherlock then whispered something, and the stranger looked away, nodding. Sherlock grabbed the stranger's shirt and turned him around, looking angry now. The stranger tugged his shirt from Sherlock's grasp and said something, tilting his head slightly. Then Sherlock literally, physically stomped his right foot on the ground, shouting. He turned and looked away, crossing his arms. Sherlock was blinking rapidly, appearing to be on the verge of tears. The stranger walked around in front of him and knelt slightly to meet his gaze. A sad look, an apparent apology. Then Sherlock crumpled into his arms, tears on his cheeks. "Is he okay? Who's that?" John's mother questioned.
John jumped not having noticed her next to him, then shrugged. "I don't know, but Sherlock seemed to trust him."
When he looked back outside, Sherlock had a pleading expression on his face. The stranger said something and Sherlock sighed, pointing at John's house as his lips formed the words "John Watson. He then jabbed his thumb behind him and said something about school. Then he sighed again, shrugged, and looked at the ground. The stranger smiled, then handed a piece of paper to Sherlock. Sherlock, examined it, then grabbed the stranger in a hug. Sherlock then grabbed his wrist and started pulling him towards the front door. The stranger uneasily said Sherlock's name, and Sherlock frowned. John made an attempt to read Sherlock's lips as he said his next sentence. "Then I'll go with you."
Now it was John's turn to frown. The stranger seemed to decline Sherlock's suggestion, and Sherlock seemed angry. John glanced at his mother as she opened the window a small bit. Just enough to be able to slightly hear them. "He'd understand! It's the last day you're here and, for once, I actually want to spend time with you! Sherlock shouted.
"Is that sentiment? He's your friend, Sherlock, and I don't even have any plans," the stranger urged.
Sherlock groaned, exasperated. "Oh my God, Myc, I don't care as long as we do something. I want at least one good memory for the next four years I won't see you. At least give me that."
The stranger opened his mouth to protest, but nothing came out, so he gave an exasperated eye flick and sighed. "Why don't you introduce me? I need to be sure my baby brother," he ruffled his fingers through Sherlock's hair, making the latter grin and try to shove him off. "is in good hands."
"Baby brother?" John's mother asked in a whisper. "Wasn't expecting that."
"That must be Mycroft," John answered.
"Promise," Sherlock ordered, turning and staring at his brother.
"All right. I promise," Mycroft replied.
Sherlock's face lit up and he smiled. He grabbed Mycroft's wrist again and pulled him to the front door. John walked over and opened it, gesturing for Sherlock to come inside. It was time the Watsons met Mycroft Holmes.