One minute, Rachel is taking a break from babysitting. The next, she's escaping the Earth on a pedal-powered interplanetary bus. It could happen to anybody.
It could. Generally it doesn't, but it could. Because what Rachel soon learns is that Earth is infected with Math, which is why we look at our solar system and see freezing balls of ice, gas, and rock whirling lifelessly through a hostile void. Everyone else sees air pirates sailing the Seven Skies of Saturn, the endless exciting fight scenes of Mars, the sullen ghosts of Pluto, and much more.
"More" including the Lighthouse of Ceres, the waypoint for all travelers of the solar system. That's where Rachel ends up, and where she finds out her hobbies of sketching and storytelling make her a genius at repairing Math-free spaceships. She loves it, and no one makes her reveal she's from the quarantined, much-feared planet Earth.
Instead they make up their own ideas of who she is and where she's from. Very dangerous ideas...