When Grace finds out that she's adopted, her biological father, who's the head of the Global 1 nano-bot injection project, urges her against getting the bar code tattoo when she turns seventeen. Stunned by the revelations, she goes home to find her adoptive family vanished, and she's determined to find them, turning to the anti-bar-code group Decode. As they uncover more information about tracking, Grace must hide deep underground and under cover, trying to discover information that will allow Decode to figure out what Global 1 is up to, and trying desperately to shut the organization down for good.