Milk is the story of Pétur, a farmer living alone in the snowy Swedish wilderness. Surviving only off of his cows, he leads a simple life but one that is haunted by the death of his wife and only child. When a mysterious stranger, who reveals herself to be death, suddenly comes knocking on his door, Pétur is forced to confront his past.

The film was inspired by Scandinavian folklore, which is incorporated into the story through Pétur's re-telling of his treasured childhood folktales. It is through these stories that Pétur learns to accept the loss of his family and find a closure that he had been denied since the death of his wife.