Alexandra Tashen is a brilliant student, adoring daughter, merry wit, and exuberant prankster. After a blissful childhood on a Texas ranch, she learns the truth: She is a refusé, an illegal refugee smuggled into the Allied Nations as an infant. Everyone from her birth region carries a harmless but detectable bit of viral DNA from a flu vaccine. If detected by the rapid genetic testing at security screens, Alex will be returned to the Federation and a likely death. Her adoptive father developed a gene therapy to mask her g-marker, but it is not fully effective. Every g-screen presents a nerve-racking one-in-ten chance of getting caught.

When her father goes missing, Alex abandons her cloistered academic life in San Francisco for a globe-trotting Commission in a desperate race to warn him of a trap that will destroy them both. As Alex dodges g-screens on her precarious and often hilarious adventure, a love triangle develops between her and two men: Eric Burton, a commanding and disgraced intelligence officer, and his blood brother, Strav Beki, a charismatic and dangerously unhinged diplomat. Betrayals mount and secrets unravel, building to the most confounding choices that people can face—choices between love, family loyalty, and moral obligation.