Bella's a clumsy little girl.

She's always injured. She has to tell the school nurse, when she starts preschool, that it's really just her - that it's not Renée (that Renée hurting her is a ridiculous idea). This is when they find out that she's an early-onset mutant: they try to check her story. They can't. They check Renée instead, they find out Renée's harmless, they send them both home and Renée has to give her daughter The Talk about mutant powers a little earlier than most parents.

She falls out of a friend's mother's car. She cracks her skull and loses four baby teeth and needs fifteen stitches in her face, twenty in her arm. They don't think she's got brain damage, but she could've.

She falls down the stairs at school in kindergarten. She tumbles, a mess of limbs she can't control, down the long hard flight of steps, too dizzy to feel the pain until she crashes through a plate glass window. She spends six days in intensive care. She gets a postoperative infection that almost kills her.

Renée and Charlie - who get along fine, despite having been divorced five years now, who always come together when it's about their daughter - start looking into solutions.

The third doctor they try says that there's no therapy for it, no drug, she's not broken, she's just clumsy. She says, as a dismissive aside, that the only assistive device for it has been pulled from the market for safety reasons. The exoskeleton - originally branded, now released to the public domain in case any of the component tech can be salvaged after the original firm went bankrupt on it - makes one's limbs respond effortlessly to one's thoughts. A wearer is better than not-clumsy, they're superhuman, like they have a mutation for grace and precision. The problem is that with that direct an interface, one malicious telepath once took over an early adopter's exoskeleton and killed sixteen people with him.

"But Bells is a mutant too," says Charlie to this doctor. "Telepaths can't touch her."

Bella is quite unaware of all the meetings that take place, all the favors that get called in, and the media circus about that device, back in circulation that her parents effectively shield her from. All she's aware of is that on her next birthday, when she turns five, she gets a kindergartener-sized exoskeleton sized just right for her with enough inserts to keep it just right while she goes on growing.

She puts it on, and her body is hers, and she can do anything.

Including, it turns out, pass the Battle School physical tests when she is six. Assistive devices are allowed, for legal reasons. Most of them won't help for the level of fitness required. Someone in a wheelchair still couldn't pass. But Bella can, she dances through the obstacle course and laughs, because when she's in her exo these are her arms and her legs and they will go where she puts them. When she takes it off she feels - half dead. Like she's made of clay. She has to go without when she washes - water's fine; soap isn't. Peeling back the extensions over her hands is one thing. Going completely copperless in the shower is another. She has to sit in the shower, lest she falls - and she hates it; if allowed she'll become a very grimy little girl.

They only bothered putting her through the physical because she passed the written and the interview. They only bothered because she showed off. She's fierce enough, smart enough, calculating enough.

They put her on a shuttle.