The story follows a young mother who, when on a day trip with her husband and son, commits a startling act of violence and, to her horror, has no idea why. The event launches an inverted and utterly surprising crime thriller whose driving force is not the 'who' or the 'what,' but the 'why.' When an investigator finds himself obsessed with uncovering the woman's buried motive, together they travel a harrowing journey into the depths of her psyche.

Based on the novel by Petra Hammesfahr. Originally broadcast on television in 2017. Originally broadcast in 2017.