Following the events at home, the Abbott family now face the terrors of the outside world. Forced to venture into the unknown, they realize that the creatures that hunt by sound are not the only threats that lurk beyond the sand path.
When Cecilia's abusive ex takes his own life and leaves her his fortune, she suspects his death was a hoax. As a series of coincidences turn lethal, Cecilia works to prove that she is being hunted by someone nobody can see.
In a dystopian 1970s America, fifty teenage boys take part in a deadly annual walking contest, forced to maintain a minimum pace or be executed, until only one survivor remains.