Phillip Reynolds Robert Lansing is a widowed, successful plastic surgeon whose charm masks a dangerous ruthlessness. When he catches his daughter Heather Reynolds Judith Chapman making love to her boyfriend, he murders the boyfriend and stages the death as an accident. Heather witnesses the crime from afar and flees the family home in terror.
A year later, after Phillip’s millionaire father-in-law dies, he and his brother-in-law Bradley Austin Thorndike Arlen Dean Snyder learn that neither of them is in the will. The patriarch, who privately blames Phillip for Heather’s drowning years before, leaves the entire $5 million estate to his granddaughter Heather Reynolds Judith Chapman, who has vanished since fleeing.
During a late-night drive, Phillip and Bradley come across a severely beaten nightclub stripper. He brings her to the hospital and devises a plan to alter her face to Heather's likeness. The woman, Jane Lynda Simon, agrees to pose as Heather to collect the inheritance and split it with him. Phillip coaches Jane for weeks, playing Heather’s voice recordings and teaching her Heather’s mannerisms.
Phillip hosts a family party to test whether Jane can pass as Heather, hoping to seal the ruse. Bradley grows suspicious when Jane refuses to play piano, a talent Heather was known for, but the rest of the family buys the act. Jane/Heather collects the $5 million and begins a wary romance with Phillip.
Returning home one day, Phillip and Jane find Bradley waiting for them. Bradley accuses Jane of being an impostor, but in the ensuing argument he suffers a heart attack. Phillip takes away Bradley’s medication and — in a cruel moment — taps out chopsticks on the piano as Bradley dies. At Bradley’s funeral, the real Heather watches from afar.
Phillip and Jane return home to find Heather, who acts as if nothing is unusual. Phillip lies to her, saying that her grandfather left all his money to a college. The trio live uneasily for days until Heather realizes that her father altered Jane’s face and decides to visit the family lawyer in Atlanta to check the will. Phillip tells Jane that he will hire a hitman to kill Heather, but in fact he hires the hitman to kill Jane.
Phillip returns to the house and tells Heather that he killed Jane, then attempts to rape Heather, but Jane escapes and knocks Phillip out with a cast-iron skillet. Heather and Jane embrace, and Heather explains that for the past year she had been staying in a sanitarium owned by Dr. Dean David Scarroll, a family friend who wanted to have her father arrested. Dean and Heather inform Phillip there was never a Jane, and Phillip undergoes a terrifying psychotic break as doctors place him in a straitjacket and take him to the sanitarium.
Jane departs the house with the medical staff, leaving Heather and Dean together in an embrace. As Phillip is incarcerated, Jane — still posing as Heather — is met by the family’s lawyers at the airport and receives $2.5 million before boarding a private jet.
