It's not possible to undo what happened in 1976. In rural South Africa a family massacre takes place; a bloodbath whose only witness is the family's black maid. Hendrik Deyer is the principal of a state-run school camp who lives nearby with his wife and their two sons, Werner and Marius. As Hendrik becomes obsessed with uncovering what happened, his wife worries about her neighbours, a poor white family whose malign influence on her son Werner is - she believes - making his behaviour inexplicably strange and hostile. One night another tragedy changes each of their lives, irrevocably. Two decades later, Werner is living with his mother and invalid father in a small Pretoria flat. South Africa is a changed place. Werner holds a tedious job in the administration department of the local university and dreams of owning his own gallery. His father is bedridden, hovering on the edge of death, and furious, as he has been for twenty years. As Werner feels his own life slip away, and his thoughts turn to murder as a means to correct the course of all their futures. He can't undo the past, but Werner's desperation to change his own his fate will threaten not only his own family but also those still living in the aftermath of what happened all those years ago.