A teen novelist, set loose in New York City after her debut sells big. A girl mutated by fever, just discovering the extent of her new supernatural powers. The dregs of the human race, fighting to survive alien invasion. In the best teen books of the year, young protagonists navigate life in our world and at the end of it. They struggle to survive and thrive in imagined universes, dead-end towns, and deep under the sea. These are the year’s most moving, heart-pounding, and engrossing teen books.