The duty manager of a seaside cinema, who is struggling with her mental health, forms a relationship with a new employee on the south coast of England in the 1980s.

Claire has always loved her son Jim and her granddaughter Sydney, but struggles to connect with her daughter-in-law, Allison. When Allison announces a big job promotion that will relocate them far away, Claire's motherly instincts are pushed to an unsettling level where she will scheme, lie and even murder to keep her son and granddaughter from moving away.