John sat in his chair, reading the newspaper as Sherlock conducted some sort of experiment involving hydrochloric acid and fingers. Just a usual day at 221B Baker Street.
The doctor looked up from his newspaper at the soft sound of someone, or something, tapping at the window. Folding the paper neatly, he stood up and went over to the window to draw back the curtains. But there was no one there. He heard the tapping noise once more and looked down to see an owl sitting outside on the sill. "Archimedes," John said quietly to himself.
He bent over to open the window and the eagle owl flew into the flat, perching on the arm of John's chair. John went over to the bird, noting the envelope it held in its beak. He took it, gently running his fingers down the owl's back. It was addressed to him and Sherlock, and the handwriting, it had to be Hamish's.
"Hey, Sherlock," John called out to him. "Would you come here for a minute?"
"Not now, John," the consulting detective replied. "Can't you see that I'm busy?"
"We've got a letter from Hamish." That was enough for Sherlock to stop what he was doing to go to John's side. Sherlock gently wrapped his arm around John's waist and took the letter from him, opening it swiftly. "Well?" John asked impatiently. "What's it say?"
Sherlock smiled softly as he began to read aloud.
"Dear Dad and Father,
Hogwarts is amazing! When we got to Hogsmeade, a huge man with a great, bushy beard (it turns out that he teaches the care of magical creatures) lead all of us first years to the docks. I got in a little boat with four other boys and we rode in them all the way to the castle. You should've seen it! The castle was all lit up and there were so many stars. I'd never seen so many before!
When we got inside, we all waited outside the Great Hall until Professor Longbottom (he teaches herbology) came to let us all in. We had to stand at the front of the room with everyone watching us. Everyone around me seemed to be really nervous about the sorting, but I wasn't. I was so excited when he finally called my name. I sat up on the stool and he put the sorting hat on my head. I could hear it talking in my head! It kept going on and on about how I am very intelligent. It almost put me into Ravenclaw, but then it changed its mind. It thought that my intelligence might help me better in Slytherin. And then it told me I've got a lot of courage, just like Dad. It said that that was exactly the type of thing it was looking for, something that wasn't completely obvious. So, the sorting hat put me into Gryffindor, just like Dad would have been in if he'd gone to Hogwa-"
Sherlock stopped speaking. "John? Are you alright?"
John nodded his head as he wiped at his eyes. "Yeah. Yeah, I'm fine."
"You don't look fine. You're crying. What is it?" Sherlock looked at him, his brows furrowed in worry.
"Really, Sherlock. I'm fine. It's just… " John smiled slightly as more tears fell from his eyes.
Sherlock finally understood. "He's more like you than you thought. He doesn't just take after me. He's brave and caring, just like you. He always has been. You just never saw it like everyone else did." He dropped the letter onto John's chair and pulled him into his arms, gently pressing his lips to John's forehead. "You need to stop thinking so low of yourself."
John couldn't say anything, too filled with emotion to try. He simply held onto the front of Sherlock's pale blue shirt as he tried to get a hold of himself.
"He'll be okay, love," Sherlock whispered against John's graying, blond hair. "He's having fun, learning things that we could never teach him." John began to laugh and Sherlock pulled away slightly to look at him with furrowed brows. "What's so funny?"
John wiped his eyes again, still smiling brightly. "Did you just admit that you don't know everything?"
Sherlock narrowed his eyes. "Oh, shut up." He rolled his eyes, smiling slightly to himself.
John smiled and leaned up to kiss him gently. "You're an idiot."
"I love you, too," Sherlock replied.
John just stared up at him, smiling still. He had finally come to terms with Hamish going away to school; he couldn't be happier for his son. John had always known that Hamish was going to grow up to be a great man, but he had thought that it would be because of Sherlock. But he had never realized just how big of an impact he had on his son's life. Not until that day. And he would never forget it.