After escaping Cordova Island, Dr. Weber and Mr. Riggs work together to analyze the soil they collected and develop a new herbicide. Anaya’s mom and both Petra’s parents join the group at the military base on Deadman’s Island, where they learn the truth of their children’s conception. They managed to keep their cryptogenic traits hidden from the rest of the world.

One week later, the herbicide is ready to be tested for the first time. It’s sprayed over black grass, pit plants, vines, and water lilies from a helicopter carrying a torpedo-sized tank of it. Nothing happens at first, but Anaya tries to be patient. After eight hours go by and there’s still no change, however, hope begins to falter. Petra’s parents say they’re needed back home, but Petra is reluctant to leave her friends. She’s also terrified of people she knows seeing how she’s changed. Dr. Weber convinces Petra’s parents to let her stay. Petra’s dad pressures Seth to have his feathers surgically removed, not understanding why Seth wants to keep them. Dr. Weber insists the choice be Seth’s. Once Dr. Weber learns other teens like these three have been identified in Canada and the US, she decides they need to be moved to a safer facility where their secret can be better protected.