In a field near New Jersey, parasitic insects attack a colony of bats, which then turn into bloodthirsty creatures. The so-called Vesps represent a deadly danger to humans, because even the smallest noise attacks the blind, flying and fast-growing monster, which have a very fine ear. The deaf teenage girl Ally (Kiernan Shipka) and her family become the target of the creatures. Thanks to the sharpened senses of the youngsters, which the attackers can sense, they first escape. But the supposedly safe forest provides only limited protection, the family must live in complete silence. In the midst of this life-threatening chaos, they realize that even humans can become dangerous when it comes to the struggle for life and death.