2165 Rangers are the only connection between the Earth, long taken from people, and flying stations - the last stronghold of humanity. Sionna Vale is the best in the business. It would seem that nothing can shake her self-confidence. But after the girl is assigned a partner, everything changes. As she navigates a series of strange events, Sionna finds herself at the center of political intrigue and the consequences of her past. And she understands that her idea of the world - at the stations and beyond - is unbearably far from the truth.