In a future world, Tyler, though the top of his class, misses his chance to pick the best team by being absent, rescuing a young woman, Aurora, from a shipwreck lost in the Fold (interstellar FTL travel place).
His twin sister and best friend refused all offers, but the other three team members (two of whom are non human) are literally the last choices, and they are sent on a literal supply run to some refugees. And meanwhile the young woman is seeing things, and when a nurse assures her that everything is fine and she should go with the ship that's being sent for her, she also slips her a note telling her to stow away in a specific ship.
It unfolds from there. It involves an alien race's civil war, how Tyler's father died, the question of where Aurora was going, a caper, a proverb of a non-human race about family, diamonds, the hints of precursor races, and more.