In England, officials were shaken when they discovered the body of a young girl while dragging a lake, an apparent case of suicide that troubles the community. Meanwhile, in the beautiful setting of Nice, France, a charming and handsome chauffeur named Bob prepares for the arrival of Penny Appleby, a young woman in her late teens or early twenties who has been confined to a wheelchair due to a tragic horse riding accident long ago. Penny is on her way to stay with her father and stepmother, Jane, who she has never met.
Upon her arrival, Jane greets Penny with open arms, although she soon reveals that her husband is currently away on business. The elegant evening unfolds at their lavish estate, but later, during the night, strange noises creep into Penny's ears, compelling her to venture outside her room. With determination, she maneuver her wheelchair to the summer house, where flickering candlelight captures her attention. However, what she finds inside is a horrifying sight: her father's corpse, sitting lifelessly in a chair! Panicked, Penny unsuccessfully attempts to process this grim discovery, racing out of the summer house only to end up in the pool where Bob comes to her rescue.
Recovering from the shock, she finds herself under the care of Dr. Gerrard, who tends to her injuries. Despite Penny’s insistence that she witnessed a gruesome reality, a search of the summer house reveals no body. Her mind begins to race as confusion sets in; shortly after, her stepmother Jane informs her that her father is just fine and is available for a phone call. This adds to the turmoil brewing in Penny's mind, as she silently ponders her father’s alleged whereabouts.
Amongst all this chaos, an unlikely friendship blossoms between Penny and Bob, who begins to show genuine concern for her wellbeing. The situation turns even more sinister when Penny encounters her father's corpse once again—this time in his study. Doubt creeps in, and she questions her sanity, but her gut tells her that something is terribly wrong with Jane and Dr. Gerrard. This leads her to suspect that her father's untimely death is somehow intertwined with their nefarious motives.
In partnership with Bob, the two embark on a harrowing journey in search of the truth, believing that her father's body must be hidden within the estate. During one harrowing midnight escapade, they attempt to pry open a meat freezer, but the discovery is far from what they hoped for. Penny's focus then shifts to the swimming pool, where she deduces that the chilling waters may conceal her father's remains. With desperation and urgency, Bob plunges into the frigid depths, revealing a haunting sight—the eyes of Penny's father staring back at him from an icy grave.
Now with the horrifying truth unveiled, Penny and Bob resolve to reach out to law enforcement, but not before a cunning encounter with Jane leads them into further peril. As they drive away, the sinister nature of their situation escalates when Penny sees her father’s corpse slumped in the front seat. In a frenzy of horror, she screams and struggles helplessly as the car accidentally plunges into the water—a calculated move that Jane and Bob had deemed necessary to eliminate the witnesses to their crime.
In the wake of this tragic turn of events, Jane receives an unexpected visit from her father’s solicitor, who sheds light on the devastating reality—the authorities recovered only one body—the father’s. To Jane’s growing disbelief, she learns that Penny had committed suicide three weeks prior! In a shocking twist, Jane spots a figure in a wheelchair near the cliff outside. Curiosity compels her to investigate, only to discover that the girl in the wheelchair is not Penny at all but rather Emily Frencham, Penny's best friend, who was never paralyzed and had come to uncover the nefarious actions of Jane and Bob.
Emily recounts how she became involved in the facade after Penny's father sought her help, guiding her to this revelation. With determination, Emily contacts the police, exposing the truth behind Penny's tragic end. As Emily triumphs in the reveal, Jane, consumed by despair, finds herself in a wheelchair that gets kicked off the cliff, leading to her death. Meanwhile, Bob, having realized Penny's survival, frantically searches the estate for her, only to be met with his own arrest. As the dust settles around these dark events, Dr. Gerrard comforts Emily, providing solace as she finds closure for her late friend, Penny, whose story comes to a tragic yet resolved end.
