Seventeen-year-old Sky Calloway knows the basics of history. The world was wonderful - until one hundred years earlier, when a horde of murderous monsters obliterated humanity, driving the few survivors to island refuges. With all boys ruined in infancy by a monster-borne plague, strong-willed women maintain the human race through medical means and boundless determination. The secretive and restrictive Order guards the small, isolated community where Sky lives, burying the painful past in the process. When Sky joins a perilous journey to the monster-infested shore to scavenge precious resources, she hopes for the freedom she has always craved. After a horrific monster attack shatters the expedition, Sky must survive alone amongst the evil creatures that roam the dark shore. Her hopeless situation alters wildly with unexpected aid from a very astonishing source. Sky's subsequent journey leads her toward the answers for questions that have long plagued her. What are the monsters, and from where did they come? What really happens to baby boys? And what does a grown man look like? Mystery, action, and romance abound as Sky faces the most difficult question of all: what makes us human?