After the first wave, only darkness remains. After the second, only the lucky escape. And after the third, only the unlucky survive. After the fourth wave, only one rule applies: trust no one. Now, it's the dawn of the fifth wave, and on a lonely stretch of highway, Cassie runs from Them. The beings who only look human, who roam the countryside killing anyone they see.

The enemy is Other. The enemy is us. They're down here, they're up there, they're nowhere. They want the Earth, they want us to have it. They came to wipe us out, they came to save us. But beneath these riddles lies one truth: Cassie has been betrayed. So has Ringer. Zombie. Nugget. And all 7.5 billion people who used to live on our planet. Betrayed first by the Others and now by ourselves. In these last days, Earth's remaining survivors will need...