Puck has been invited by her tutor at the university to celebrate midsummer at his secluded cottage on an island together with a group of friends, among them Einar Bure. Puck and Einar is having a secret relationship, and he is the reason she says yes to the invitation. The summer nights are seductively beautiful and erotic tensions are rampant between the guests. Having been out on a romantic spree with Einar, Puck finds one of the female guests murdered. Einar contacts his friend Christer Wijk, but upon Christers arrival, the dead body has disappeared. The contact with the outside world is broken when the islands only boat goes missing. They are trapped on the island - and someone amongst them is a killer. Under these circumstances Puck get to know both Einar and Christer. But before the murderer is exposed, two people have been killed, and one person has committed suicide.