Best friends Kayla and Mishalla know they will be separated for their Assignments. They are GENs, Genetically Engineered Non-humans, and in their strict caste system, GENs are at the bottom rung of society. GENs are gestated in a tank and sent to work as slaves as soon as they reach age fifteen. When Kayla is Assigned to care for Zul Manel, the patriarch of a trueborn family, she finds secrets and surprises; not least of which is her unexpected friendship with Zul's great-grandson. Meanwhile, the children that Mishalla is Assigned to care for are being stolen in the middle of the night. After weeks of toiling in their Assignments, mystifying circumstances enable Kayla and Mishalla to reunite. Together they hatch a plan to save the disappearing children. Yet can GENs really trust humans? Both girls must put their lives and hearts at risk to crack open a sinister conspiracy, revealing secrets no one is ready to face.