Now, when the first four waves of foreign invasion decimated mankind and destroyed the greater part of the world, survivors await the fifth, decisive wave. They can not trust anyone, because everyone can be a messenger of strangers. Cassie (Chloë Grace Moretz) is a desperate, all he wants is to protect his little brother. In preparation for the fifth wave, he joins forces with a young man, perhaps the only hope of finding his brother. But can he trust him?