Midsummer's Eve, 1974, in the far north of Sweden. Annie Raft arrives with her six-year-old daughter Mia in a small town called Blackwater to join her lover Dan on a commune. But Dan is not there to meet them. Panicking, Annie treks into the wilderness to find the commune, in the strange light of midsummer night. In the woods, an oriental-looking man runs past, without seeing her. By the river, she finds a tent, and inside it two bodies hideously murdered—stabbed so violently that the feathers from their sleeping bag scatter the ground.
Many years later, Annie has settled in the region, and Mia, her daughter, has grown up. Early one morning she glimpses sees Mia in the arms of the man she believes responsible for the murders. The seemingly inexplicable crime—long buried—is forced at last to come to its own dark and quite unexpected conclusion.