Officially, Grace and her friends are underage aliens on the run from the authorities, revolutionary gangs, and their families. Unofficially, they are screwed. For an Earth-girl who always has a solution, falling through a portal to an alien mining world leaves Grace without a quick fix. But she's got this, she can survive anything with her friends at her side-until they disappear. Trapped and running out of time to find a way home, Grace must navigate the rugged terrain of an underground world that is tipping into environmental destruction and social revolution, while trying to find her missing friends and the ex-boyfriend who betrayed her.