*I received this ARC as part of the Goodreads First Reads Giveaway from the publisher*On a day like any other day, the Others arrived. Their mothership lit up the sky and the human race was forever changed. The Others came in waves taking away electricity, bringing upon the world a plague, sending out evil drones to take care of the survivors, and now, they have taken on the form of humans. The idea of trust (or lack of there) and the depths that humans will sink to survive are constantly replayed over and over through the actions of the multiple protagonists that Yancey introduces in the story. We meet the main protagonist, Cassiopeia “Cassie” Sullivan when she is at her lowest point, alone in the woods for an extended period of time replaying the last day she saw her family and the promise she made to find her little brother Sammy. Cassie is smart, and tough, and not the girl she used to be before the invasion. She is willing to kill and fight for her life, and the only thing that keeps her going is the idea of being reunited with her brother. Cassie also knows that she has to stay isolated because she cannot trust that the people she meets on the road to her brother are human. Cassie’s mind starts to disintegrate as she becomes further and further removed from humanity and the life she once lived. All that changes, however, when she is rescued by Evan Walker, a mysterious farm boy with a special smile who only wants to help her get well enough to find her brother. Evan is charming and smart, but there is something about him Cassie cannot shake. He is too perfect, too sweet, and he knows all the right answers to her questions. Cassie has to put all of that doubt aside though, because Evan is her only hope in finding her brother and keeping her promise. Together these two teenagers and their choices could be the savior or destruction of humanity. As long as they can stop the 5th wave… This is by far and away, the best book I have read all year. The characters made me physically hurt when they hurt. Rick Yancey creates just the right amount of tension and despair to capture the reader and never let them go. The characters define this story, and while an alien invasion is what catapults the action, the aliens really take a back seat. It is Cassie, Evan, Sammy, Zombie, and their reactions to the invasion that really spoke to me. They all struggle internally with their new lives and the new people they have become. Yancey brings up the questions of: what makes us human? Is it the way we look? Is it the connections that we make? The way we behave? Or is it our capacity to love and care about each other that makes us human? If that is the case, how different are humans from the aliens?