"We don't call ourselves mayflies because we're so delicate and beautiful, but because mayflies only live for a day." - Yunko sayingDeep into its Sixth Mass Extinction, Earth still chirps, growls, squeaks, and reeks with life. Screams with life. Screams with death, too, unheard by its dominant species. This clamor of life overloads our Yunko senses-so much keener than those of Earth's native Sapiens-unless we constantly filter input. We must also conceal this greater sensory awareness from Sapiens; Sape curiosity is the second greatest threat to our hidden existence. The training manuals for our field research teams include twice as many regulations for Seconds as for Researchers. This is not a criticism of our young people, who make it possible for Researchers to do their jobs. The imbalance simply acknowledges that Seconds are thrust into a more dangerous security situation. When they first go into the field, they are still too young to fully comprehend the need for secrecy. Their genome, more than 96 percent Homo sapiens sapiens, resonates with Sapiens of the same age, creating a desire for dangerously close connections with Sapiens teenagers.Seventeen-year-old Goran Helin can pass for human if he keeps to himself, keeps his clothes on, and keeps his mouth shut. After all, less than 4 percent of his genome comes from a planet 23 light years away. If he follows the first rule of his hybrid alien-earthling people--never get close enough to humans to reveal your true nature--he'll die of old age at 32 like the rest of his Yunko kind. But Goran breaks the rule, then flees across climate-hammered, xenophobic, near-future Washington State and British Columbia with his forbidden human co-conspirators in a wild effort to restore his people's normal lifespans. He hopes his people will reward him as their savior instead of executing him as their betrayer.