The Infinite Sea is a young adult science fiction romance novel written by American author Rick Yancey. Published in 2014, the novel is the second in The 5th Wave trilogy. After fleeing from a camp established by aliens, 16-year-old Cassie Sullivan, her brother, and a squad of child soldiers attempt to prevent the extermination of the human race. The novel provides detailed histories of the side characters from the previous novel. Instead of just narration from Cassie, the narration shifts from the point of view of Ringer, another teenage girl. Source: Wikipedia (en)