Rowan Caine becomes a live-in nanny in a remote smart house in Scotland, where she looks after three children. The job quickly turns unsettling as the house feels eerie, the children behave strangely, and past tragedies surface. Cut off from the outside world, Rowan’s mental state deteriorates. After a child dies, she is arrested for murder, but she insists she is innocent and that the truth is more complicated than it seems.