It's the last day of school. Christian (19) and his younger sister Sofie are on their way to a party together with their friends. They've got to finish studying for their finals, take the tests themselves, and then school's out for good. The party has come just at the right time, and is just what Christian needs; right up until the point his sister commits suicide in an upstairs bathroom. Exams and graduation completed, Sofie's unexplained suicide is still affecting everyone concerned, especially Christian, who is convinced that Sofie was trying to tell him something before she killed herself at the party. But life has to go on, and before they all have to split up and go their own way Christian and his friends decide to go on their traditional trip to Sweden to celebrate midsummer for one last time. Although the group's usual rituals in connection with the midsummer trip aren't the same without Sofie, everyone does their best to enjoy themselves. And when Christian's long held, yet unrequited feelings for the beautiful Trine finally appear to be reciprocated, it looks like the trip is going to turn out just fine anyway. But then Christian discovers that someone - or something - has decided that Sofie's suicide should not go unexplained - and one night he wakes up with the feeling that Sofie is in the room with him. Has Sofie really come back? Or are Christian's feelings of guilt and sorrow over Sofie's apparently meaningless death making him imagine things? The dreadful truth is lurking in the dark shadows cast by the fir trees in the Swedish forest. The trip turns out to be like nothing they've experienced in the past - and the lives of those who get to drive back home after midsummer is over will never be the same again.