A/N: This is a prompt by Agatha Doyle!
"Come on Mycoftt!" Holmes little voice yelled at the bottom of the stairs.
"What could you possibly want?" Mycroft Holmes's voice rang out all throughout the house scaring 7 year old Sherlock.
"A mystery has arisen!" the younger Holmes shouted. "It is a wery important case!" Mycroft stomped down the spiral staircase.
"What did you lose?" Mycroft sighed as if it wasn't the first time he has asked him to look for something, first it was his pet lizard Edgar now this.
"I didn't wose anyting!" Mycroft stared at him. "I'm serwious!"
"Alright, fine lead me there." Sherlock grasped his small hands around Mycroft's tweed jacket.
"Tis' way!" Sherlock began walking.
A few minutes later they stopped right outside the Holmes's house, where a small creek slowly drifted down the lawn.
"ALright, what is it?"
"Look! Right there!" Holmes pointed right next to the creek, where a small envelope with the letters 'M.H.' on it.
"That is peculiar," Mycroft bent down. "Alright Sherlock, listen up this is our first big case!" Holmes's grin was from ear to ear. He bent down next to his brother.
"Look at the letters! Mycoft those are your initials! It must be for you open it!" Sherlock looked at him eyes wide. Mycroft sighed.
"Alright if I must." He opened the letter carefully. A small white paper fell from it.
"Read it!" Sherlock yelled.
"Hush little brother! I will." Mycroft glanced down at the paper his eyebrows furrowed. The letter looked like it was a teenagers handwriting. "It only says 'Wait until you're older more fun will begin.' "
"More fun we've solved it we will have more fun!" Sherlock ran around happily, but what Mycroft didn't tell him was that it said 'From J.M.'
"Sherlock we still have to figure our how it got here." Sherlock stopped.
"Isn't obvious? The wind! It must of blown out from you're window when Nanny brought it to your room!" he indicated the open window.
"Way to go Sherlock you've solved it!" Mycroft faked smiled.
If he only knew.
A/N: I guess you could call that Sherlock's first case. Anyway where things are misspelled I did that on purpose for Sherlock's little 7 year old lisp!