I've injured myself somehow and I'm tired and crabby, I thought writing an alternate universe with kid!John and kid!Sherlock might cheer me up. It ended up kind of being angstier than I intended. Oh well...
John rubbed his eyes and shouldered the backpack that was nearly as large as he was. He'd packed all the important things - a few jumpers, his favourite books, and some of the biscuits his best friend liked so much. He winced as the bag grazed the bruises his mother had left on his back, exacerbated by his hag of a sister when he'd gone to her for help. She'd called him a sissy for being unable to defend himself and added nasty bruises of her own.
John debated leaving a note, but knew it was pointless - it's not as if he had many places to go. Inevitably his mum would call Mrs. Holmes, pretending to be distraught and penitent. At least if he left tonight he'd have one or two days of peace and quiet.
When he got there, both brothers were at the door waiting. Sherlock welcomed him warmly but Mycroft looked irritated. "Do you think this is a good idea?"
"John is my friend, and he's welcome to stay in my room as long as he needs. Now butt out before I tell mummy you've been meddling with the household finances again."
John's heart warmed. Sherlock had stood up for him, stood up to his sibling. Something John just wasn't able to do. Sherlock was so brave.