I am a movie director and I just received the following movie plot. Could you help me answer this question? If not, let me know by writing "Not answerable". Plot title: Full Circle Movie plot: Julia Lofting (Mia Farrow), her husband Magnus (Keir Dullea), and their young daughter Kate (Sophie Ward) eat breakfast and Kate starts to choke on a piece of an apple. When the apple refuses to dislodge, Julia reaches for a knife and tries to perform a tracheotomy on Kate's throat, but fails and Kate bleeds to death.Distraught by the death of her only child, Julia leaves her husband and moves to a new house; a mysterious old row house in a low part of London. An upstairs room contains a child's possessions. As she unpacks, Julia finds a mechanical clown toy with sharp, clanking cymbals and accidentally cuts her finger on them.In a nearby park, Julia thinks she sees Kate, but the girl disappears. She hears strange noises in her house, blaming them on Magnus, who she believes is spying on her. When Julia takes photos of the child's possessions in the room, she is baffled when there is nothing in the frame of the developed photo and sees that the items cannot be photographed. A radiator in the house mysteriously turns on by itself. Later, Julia sees the girl in the park, but finds a mutilated turtle and a knife where she stood.Magnus' sister, Lily, asks Julia if her friends can use her house to conduct a seance. The medium, Mrs. Fludd, explains that spirits need to control someone to carry out physical acts. During the seance, Mrs. Fludd becomes frightened and tells Julia to leave the house immediately. Moments later, one of Lily's friends, Miss Pinner, falls down the stairs.While Julia is out, Magnus breaks into her house to find her. He sees something and follows it to the basement, but is killed after falling from the staircase - his throat cut on a broken bottle.A neighbor tells Julia the house once belonged to Heather Rudge, who moved away after her daughter Olivia choked to death (in a similar manner to Kate). Julia visits Mrs. Fludd, who has taken ill since the seance. She tells the medium she is convinced her house is possessed by Kate's spirit, but the medium tells her she saw a boy in the park,... My question: Who did Olivia murder?
Mrs. Rudge