She starts calling herself "Tab", for short, not that anyone calls her anything apart from Kers. She writes suitably encrypted emails to Aelise about ideas for fixing the world - mostly she asks questions, to start, forming a picture of the exact problem she has to solve.
She misses her parents, but not very much. At least she got to say goodbye.
When her brain won't absorb new information, she bounces around in zero-g.
After six months, Aelise visits again.
Tab says, "Anybody you store up here must be important somehow. If I don't know about the other secret person, I won't know how to come up with ideas that work with them being important however they're important."
"What do you want to know about him?" says Aelise.
"He is up here for complicated reasons," says Aelise. "I'm not sure what the best summary is."
"Not while you're still seven."
"I could also just introduce you to him and let him tell the story himself," she says, "but I'm fairly sure that if he finds out Kers is up here he will find a way to kill her, and I don't know how good you are at maintaining that kind of information security."
"Something tells me he won't think of that," says Aelise. "Besides, he doesn't have to know you live up here."
"That would be a good idea."
"All right," says Aelise. "And there's a small chance he might try to hurt you, but Kers can keep you safe."
Some time later, Tab gets an email that says she can visit section 214 whenever she wants, as long as she pretends she still lives on Earth, pointedly refuses to answer questions about how she got there, and makes sure not to imply she has ever met Kers.
And the name of the person living there is Harley.
She says yes.
"Good for Aelise," says Harley, at a somewhat more normal volume; he's only just around the corner now, and then he isn't. He is in a room in the section's living quarters, with a book open on the computer, lying in bed rather than reading it, wearing a pair of rumpled pajama pants in sky-blue dotted with fluffy white sheeps. He is maybe sixteen or seventeen years old.