One day, gravity on Earth suddenly became a fraction of what it is now. Twenty years later, humanity has adapted to its new low-gravity reality. And to Willa Fowler, a woman born just after G-day, it's...well, it's pretty awesome, actually. You can fly through the air! I mean, sure, you can also die if you jump too high. So you just don't jump too high. And maybe don't get mixed up in your Dad's secret plan to bring gravity back that could get you killed...