Living in a dystopic future, Leah and her younger sister Rachel are fighting to survive in a world thats becoming increasingly unlivable. Earths atmosphere has been poisoned by pollution, so each year the governmentTerraholds a contest for all eligible, healthy 16-year-olds. The winners, 100 teens who possess skills that will contribute to Venuss floating biosphere, are sent to the Floating City. Though both Leah and Rachel are talented gardeners, Leahs pollution-induced asthma makes her ineligible. After Rachel is selected for the Floating City, she tricks Terras medical staff and sends Leah in her place to save Leahs life. Once on Venus, Leah continues to hide her true identity. She is assigned to work in the citys greenhouse where she meets Rose, who awakens something inside her she never knew existed. But when Leahs asthma returns, shes forced to find out whether true love can survive deceit, and if her sister's sacrifice was ultimately worth the price.