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.

Sonja lives a rather carefree life with her beloved family. The husband Frederick's marijuana business providing family finances a silver lining. But life is shattered and Sonja forced to play a dangerous game with both organized crime and police to protect their children. She can no longer be sure which ones are her friends and who she can trust.