Several friends travel to Sweden to study as anthropologists a summer festival that is held every ninety years in the remote hometown of one of them. What begins as a dream vacation in a place where the sun never sets, gradually turns into a dark nightmare as the mysterious inhabitants invite them to participate in their disturbing festive activities.
A stranger arrives in a little village and soon after a mysterious sickness starts spreading. A policeman is drawn into the incident and is forced to solve the mystery in order to save his daughter.
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.
Chris and his girlfriend Rose go upstate to visit her parents for the weekend. At first, Chris reads the family's overly accommodating behavior as nervous attempts to deal with their daughter's interracial relationship, but as the weekend progresses, a series of increasingly disturbing discoveries lead him to a truth that he never could have imagined.
Grace is a woman who lives in an old house kept dark because her two children, Anne and Nicholas, have a rare sensitivity to light. When the family begins to suspect the house is haunted, Grace fights to protect her children at any cost in the face of strange events and disturbing visions.