Rumor Mora fears hellhounds too strong for him to kill, and failure. Jude Welton dreams that humans will stop killing monsters, and his strange abilities will vanish. In no reality should a boy raised to love monsters fall for a boy raised to kill them. Nyx Llorca secret is that the moon speaks to her, and she's in love with her best friend, Dahlia. Braeden Tennant wants to get out from his mother's shadow, and to unlearn Epsilon colony's darkest secret. During one twenty-seven-hour night, these four runaways must stop the war between the colonies and the monsters from becoming a war of extinction, or the things they fear most will be all that's left.