In the vibrant backdrop of 1970s New York City, we follow David Marks (son of influential real estate developer Sanford Marks) as he makes an unconventional choice by marrying Katie McCarthy, a bright and ambitious woman from a modest upbringing. Their journey takes a significant turn as they move to Vermont, where they open All Good Things, a health food store that symbolizes their dedication to a healthier lifestyle. However, Sanford's manipulative tactics soon pull David back to the city's opulent chaos, planting seeds of doubt about Katie's lifestyle choices.
As time goes on, Katie expresses her desire to start a family, but David steadfastly refuses, leading her to incorrectly assume that he struggles with fertility. This misunderstanding sets off a chain of events that would tragically alter their lives. The couple’s dreams are further complicated when they acquire a lakeside retreat, where Katie confides her pregnancy to their neighbor. David's explosive reaction to the news culminates in a heated demand that Katie terminate the pregnancy, a request she grudgingly complies with.
As Katie pursues her educational aspirations by enrolling in medical school, her relationship with David continues to fray. Attempts to separate from him meet strong opposition, especially when David cuts off her access to financial resources vital for her education. In desperation, Katie embarks on a mission to uncover incriminating financial documents that could provide her leverage in the crumbling marriage.
Tragedy strikes in 1982 when Katie mysteriously disappears, leaving behind only a tantalizing clue and a $15,000 reward for any information regarding her fate. Eighteen years later, the investigation is reignited after the discovery of a previously unpublished novel written by David's best friend, Deborah Lehrman. This novel eerily mimics the circumstances surrounding Katie's disappearance, once again drawing the authorities' attention to David.
In a shocking twist, investigators also link David to the murder of his neighbor, Malvern Bump, in Texas. Though he is acquitted, the stain on his character lingers, as does the enigma of Katie's fate. Her disappearance continues to puzzle not only the authorities but also the public who remain captivated by the mysterious circumstances.
The film concludes with a haunting flashback that suggests David may have hidden his wife's remains in the trunk of her car, an unsettling discovery made by his father. In a poignant moment, David visits his ailing father and whispers with deep sorrow, > "I miss her so much." This statement leaves the audience questioning whether David mourns for Katie or his mother, enveloping the truth in a cloud of ambiguity that lingers long after the credits roll.
