Opal has been planning to go to Chicago and join the Midwest's superhero team, the Sentinels, since she was a little kid. That dream took on a more urgent tone when her superpowered dad was unjustly arrested for protecting a neighbor from an abusive situation. Now, she wants to be a superhero not only to protect people, but to get a platform to tell the world about the injustices of the Altered Persons Bureau, the government agency for everything relating to superpowers. But just after Opal's high school graduation, a supervillain with a jet and unclear motives attacks the downtown home of the Sentinels, and when Opal arrives, she finds a family on the brink of breaking apart. She meets a boy who's been developing secret (and illegal) brain-altering nanites right under the Sentinel's noses, another teenage superhero-hopeful who looks suspiciously like a long-dead supervillain, and the completely un-superpowered daughter of the Sentinels' leader. Can four teens on the fringes of the superhero world handle the corruption, danger, and family secrets they've unearthed?