| Director | Seth Holt |
|---|---|
| Box office | $800,000 |
Two men recover the body of a young woman inside a Swiss lake. Robert, the family chauffeur, transports Penny Appleby, a wheelchair-using heiress, to her estranged father's estate on the French Riviera. For the past ten years, Penny lived with her mother in Italy after her parents had divorced. When Penny arrives, she is greeted by her stepmother Jane, whom Penny has only just met. Jane informs her that the father has been called away on business. She cannot say when he will return or why he left when he was expecting Penny's arrival.
Although Jane tries to be hospitable, Penny does not trust her. Later that night, Penny sees a candle lit near her father's corpse inside the summer house. She falls inside the pool while screaming for help. After she is saved, Penny insists on returning to the summer house where the corpse is not there. Jane tries to convince Penny that her stressful travel has caused her to hallucinate. Gerrard, the family doctor, arrives and gives Penny a sedative.
The next day, Robert meets Penny privately to say he believes Penny did see something unusual, even if not a corpse. Shortly after, Penny converses with her father over the telephone. Nevertheless, Robert offers to help her investigate and later finds freshly burnt candle grease, confirming Penny's claim. Over dinner, Gerrard cites Penny's past neurotic behaviour to support his theory that she experiences hallucinations.
Penny continues to experience strange occurrences, such as hearing her father's piano playing, seeing his sports car inside the garage, and her father's corpse slumped in a chair inside her bedroom. Gerrard is invited back for dinner, where he theorises Penny's psychosis is affecting her mobility. Penny disputes this and affirms her disability, which was caused by a horse falling on her legs.
The next afternoon, Robert speculates Penny's father has been murdered, and Jane and Gerrard are trying to conceal it, but has been unable to prove it. When Jane steps out, Robert deep dives inside the pool area and locates the corpse of Penny's father lying below. On their way to the police station, Robert and Penny spot Jane along the road. Robert steps out and leaves the car in drive, where it plunges over the cliff with Penny and her father's corpse inside.
Back at the estate, Robert and Jane embrace each other, believing their plan has succeeded. During the investigation, Spratt, a police detective, disputes Jane's claim that her husband and stepdaughter drowned together. Penny had drowned herself three weeks prior in Switzerland, while staying with her friend Maggie Frenham. Jane is bewildered and returns to the estate where Maggie is there. Maggie (who has been impersonating Penny) explains that Penny's father had already known his daughter had died, and she presumed the letter asking for Penny to return home was forged. Maggie and Gerrard then worked together to expose the murder.
Now wanted for murder, Robert pushes Jane off a cliff where she falls to her death. The police follow Robert and arrest him.