The 5th Wave (The 5th Wave, #1)

"After the 1st wave, only darkness remains. After the 2nd, only the lucky escape. And after the 3rd, only the unlucky survive. After the 4th wave, only one rule applies: Trust no one. Now, it's the dawn of the 5th wave. On a lonely stretch of highway, Cassie runs from Them. The beings who only look human, who roam the countryside killing anyone they see. Who have scattered Earth's last survivors. To stay alone is to stay alive, until Cassie meets Evan Walker. Beguiling and mysterious, Evan may be her only hope for rescuing her brother and even saving herself. Now she must choose: between trust and despair, between defiance and surrender, between life and death. To give up or to get up. Cassie Sullivan gets up."