Terror in Rock 'n' Roll Önsjön: The year is 1943 in Trondheim (Norway) and the nazigermans is trying a new experiment. A experiment to create "Super Soliders", but it didn't succeed. The germans canceled the experiment and order some soliders to dump the chemicals in a lake in Sweden called Önsjön. During the mission, the swedish military opend fire at the germansoliders and the bottom of the lake became the soliders grave. 30 years later, some teenagers are going to a musicfestival at Önsjön during their summerbreak. Party, beer and naked bath. It seemed to be a great festival, until the dead began to walk again.