Sherlock knew he was in for a long, sleepless night even before they got home. The combination of the past few days' events and the nap he'd taken earlier - he really wished he hadn't done that - had left him jittery, nervous, and above all wide awake. He'd estimate there was at best an eleven per cent chance that he would fall asleep tonight, based on data from past scenarios. Mycroft might have been able to help, or perhaps Mummy - but he wouldn't think of that. As high-strung as he knew his emotions were at the present, just the thought of either of the two put a pit in the center of his abdomen and sent a surge of anger to his mind so strong it made the cut on his head hurt. It would be difficult to regulate his emotions at the present moment - such things were therefore not even worth thinking about.

He had to occupy his mind somehow, though. He couldn't just do nothing. It wasn't even an option.

He wandered over to his bag, now neatly packed once more in preparation for what he felt was near to come, and pulled out his familiar chemistry textbook and a notebook and pen that Mrs Johnston had given him. In the back of the text were were a sample of practice problems he hadn't completed in at least three weeks, just long enough that he couldn't name the answers off of the top of his head. They were familiar, for certain, but he didn't have them memorized, and they were at least somewhat difficult, unlike all of the problems in the first nine chapters. He could probably recite the whole book nearly verbatim by now, to be honest.

When he next checked the clock on the wall, it read 9:14. It had been a little over an hour and he had already finished nearly all of the practice problems.

No, he was definitely in for a long night.

Hours later, when he had literally done every single practice problem in the book, when he had recited every poem, every list, every number he had ever memorized to more than a hundred digits - in short, when he was so bored that he could scream - he gave up and snuck downstairs to get a book or three.

He made it all the way to the bookcase without incident, and when he had an armful of books, enough to occupy him for at least a few more hours, he turned around and saw Rob sitting on the armchair in the corner watching him. They stared at each other for a moment. Ron broke the silence first.

"You couldn't sleep either," he observed.

"No," said Sherlock warily.

"The crash?" asked Rob.

"Among other things," Sherlock replied. Rob smiled, a wry little grin that was very much out of place on his young face. "You couldn't sleep either, I see."

"No," Rob said simply.

"The crash?" Sherlock asked. Rob grinned.

"Among other things," he said. Neither spoke for several minutes, only watched the other.

"You and John aren't the only fosters, you know," Rob said suddenly, breaking the silence.

"Obviously," said Sherlock, an ironic tone to his voice. It was certainly clear that Cassie wasn't Mrs Johnston's flesh and blood.

"It's not just you and Cassie either," Rob told him in a tone that suggested Sherlock was being somewhat stupid. Sherlock rankled at his voice, but he didn't say anything. "You know that the only one of us who are actually biologically hers is Michael? Cassie and Charlie are both adopted, and I'm just here in long term placement." The slightly bitter tone his voice took on at the end belied his age as Sherlock had estimated it, and he could tell that Rob clearly was not quite what Sherlock had thought. He raised a brow.

"Why?"

The question itself was certainly simple, but its meaning was anything but. There's always a reason you're in foster care. However good you might have it now, something had happened beforehand that necessitated being placed here.

"Do you really want to know?" Rob said. Sherlock shrugged, but his curiosity was piqued. "Ever heard of Fetal Alcohol Syndrome? Basically, it means my birth mother downed so much alcohol while she was pregnant that I got epilepsy and severely stunted growth. How old would you guess me to be?"

"My initial assumption was no older than eight," Sherlock said.

"I'm eleven and a half," he said, and Sherlock couldn't stop a surprised look from coming to his face. Rob saw it, of course. "Yeah. That's about where people usually place me. But st least I'm clever, right? Could've been my brainpower that was stunted, or both. I could've been a vegetable. Not that I should complain. They never expected me to be able to walk, much less run or climb a tree or do freaking origami." Sherlock nodded. What was there to say? "Anyways, that's my tragic backstory. It's your turn. Spill the beans - tell me why you would be a perfect human being, if only your sad life hadn't beaten the crap out of you and then put you in the foster care system."

"What do you want to know?" Sherlock asked, trying to find a loophole to sidestep the question with. He was foiled by Rob's very simple answer.

"Why are you in the foster care system?"

"My brother."

"You'll have to elaborate a bit more than that." Sherlock sighed.

"We had been home alone for almost two weeks. We were fine - Mycroft was working odd jobs, I had a newspaper route, and John took care of the house - we even kept the driveway shoveled. Everything was fine. And then one day the fat lazy git decided he didn't want to walk home after school, and he got a ride, and somehow they figured it out and they called the police and long story short? This is our fourth placement together, probably our last, and when Mrs Johnston decides that seven kids is just a few too many to take care of, especially when they all have medical issues, and realizes that she could ever so easily cut her load almost in half by sending us along to some other placement - placements, I should say, because there aren't any more that will take us all - well, it's only the most practical decision. 'It's not because we don't love you - it's not that there's something wrong with /you/ - we just don't feel like we can't take care of you anymore' - I know how it goes," Sherlock finished, a bitter twist to his own lips. "It's never my /fault/ - it's just that, you know, I'm too much of a worry and and a bother, and they're sure that the /next/ placement will be better for me." Rob nodded; he understood. After a moment, he picked the book he had been reading before Sherlock had come downstairs back up and went back to reading it as though he had only just put it down.

And maybe Sherlock felt just the smallest bit of respect for this angry, bitter boy who understood what it meant to be just a foster child.