A teenage girl is captured by a giant mutated squid-like creature that appears from Seoul's Han River after toxic waste was dumped in it, prompting her family into a frantic search for her.
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.
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.