Knives Out Film Synopsis

A wealthy patriarch’s sudden death unleashes greed, suspicion, and betrayal within his entitled family. A sharp detective unravels secrets, while a devoted nurse becomes entangled in deception, inheritance, and a dangerous scheme. Hidden motives surface, leading to shocking revelations that expose the true manipulator behind the family’s unraveling.

The Birthday Gathering

The story begins at the grand estate of Harlan Thrombey, a famous and wealthy mystery novelist who has invited his extended family to celebrate his 85th birthday. The mansion is a sprawling, Gothic-style property filled with Harlan’s eccentric decorations, books, and heirlooms. Members of the Thrombey family arrive, each with their own expectations, grievances, and hidden motives. Though the party appears cordial on the surface, tension brews beneath the polite exchanges.

The next morning, Fran, Harlan’s loyal housekeeper, discovers her employer dead in his study. His throat has been slit, and blood stains the front of his nightshirt. Though shocking, the initial assumption by both family and investigators is that Harlan has taken his own life.

The Initial Investigation

Local law enforcement is called in. Lieutenant Elliott and Trooper Wagner arrive to interview the family. They ask questions about the night of the party, Harlan’s mood, and the relationships he had with his relatives. The police quickly lean toward suicide as the cause of death, given the locked-room nature of the scene and the lack of immediate evidence of foul play.

However, a private detective, Benoit Blanc, is also present. His presence surprises the family. Blanc, known for his eccentric Southern drawl and sharp investigative mind, reveals he was hired anonymously with a retainer fee to investigate Harlan’s death. The mystery writer’s passing has caught Blanc’s attention, and he believes there may be more to the story.

Motives in the Family

Blanc interviews each family member individually. Tensions quickly come to light. Linda, Harlan’s eldest daughter, prides herself on her independence but still benefits financially from her father’s wealth. Richard, her husband, hides an affair that Harlan discovered. Walt, Harlan’s son, manages the publishing company but resents his father’s refusal to allow adaptation rights for his novels. Joni, the widow of Harlan’s late son, lives lavishly while secretly siphoning tuition money meant for her daughter. Ransom Drysdale, Harlan’s rebellious grandson, is openly antagonistic toward the rest of the family. Each interview reveals potential motives rooted in greed, resentment, and entitlement.

Despite their insistence that they loved Harlan, Blanc recognizes a pattern: nearly everyone had reason to benefit from his death.

Marta’s Burden

Unbeknownst to Blanc and the police, Harlan’s nurse, Marta Cabrera, believes she accidentally killed him. On the night of the party, she mixed up his medication and injected what she thought was a lethal dose of morphine. Harlan noticed her panic and quickly realized the situation. To protect Marta from suspicion and legal ruin, he devised a plan in his final minutes.

He instructed her to create a false alibi: she was to appear leaving the house normally, sneak back inside through a side window, disguise herself as him, and then leave again to make it appear that he was alive after her departure. Once Marta followed through, Harlan slit his own throat to make the death look like suicide. Marta, wracked with guilt, keeps her secret.

Marta suffers from a peculiar condition—she cannot tell a lie without vomiting. This forces her to answer Blanc’s questions with partial truths. She begins to work with Blanc, concealing evidence that could incriminate her.

The Will Reading

The family gathers for the reading of Harlan’s will. To their astonishment, the will reveals that the entire estate—mansion, publishing company, and fortune—has been left to Marta. The Thrombeys are shocked and enraged. Their assumptions of inheritance crumble instantly.

The revelation sends the family into chaos. Some plead with Marta to relinquish the inheritance voluntarily. Others threaten her, with one warning that her undocumented mother could face deportation if Marta refuses. Amidst the turmoil, Ransom Drysdale, who had stormed out of the will reading, returns. He offers Marta a ride and appears sympathetic.

Ransom’s Manipulation

Ransom takes Marta into his confidence. Over a meal, she breaks down and confesses what she believes happened—that she accidentally poisoned Harlan. Ransom encourages her to trust him, promising to help her keep the inheritance in exchange for a cut of it. Marta, vulnerable and fearful, reluctantly agrees to his terms.

Meanwhile, the rest of the Thrombey family begins scheming to regain the fortune. They pursue legal avenues to challenge the will, while simultaneously attempting to emotionally manipulate Marta.

The Blackmail Note

Marta receives a mysterious blackmail note. It contains part of Harlan’s toxicology report and demands a meeting. Fearing exposure, she confides in Ransom, and the two drive to the county medical examiner’s office, only to find it destroyed by fire. The evidence of Harlan’s actual toxicology results is gone.

Soon after, Marta is contacted via email by the blackmailer, instructing her to meet. She goes to the rendezvous but is intercepted by Blanc and the police. During the encounter, Ransom is arrested for his connection to Marta and the blackmail attempt.

Fran’s Fate

At the meeting place, Marta finds Fran, the housekeeper, unconscious from an overdose of morphine. Fran had been the blackmailer, having seen Ransom tampering with the crime scene. Marta attempts to save her with CPR and calls an ambulance. Though she acts quickly, Fran later dies at the hospital.

Wracked with guilt, Marta confesses to Blanc that she believes she killed Harlan. However, she learns that Ransom has already implicated her to the police. Marta feels an obligation to tell the Thrombeys the truth, as the slayer rule—preventing killers from inheriting—would mean the estate reverts to them.

Blanc’s Revelation

Blanc, however, pieces the puzzle together. He reveals the full truth in front of Marta, Ransom, and the police. Blanc explains that Ransom learned about the will change on the night of the party and decided to ensure Marta would be blamed for Harlan’s death. He switched Harlan’s medications, intending for Marta to administer a fatal overdose and then be disinherited.

But Marta, skilled as a nurse, identified the correct medication by its viscosity rather than its label. She unknowingly gave Harlan the right medicine, meaning he was never in danger of overdose. Harlan’s death was truly a suicide. Marta only believed she had poisoned him because she later checked the swapped labels.

Fran had spotted Ransom tampering and sent him a blackmail note. To cover his tracks, Ransom burned the medical examiner’s office and poisoned Fran with morphine, hoping Marta would be discovered at the scene.

The Final Confession

As Blanc delivers his deductions, Marta receives a call from the hospital. She tells Ransom that Fran has survived and will implicate him. Believing himself cornered, Ransom smugly insists he cannot be convicted because his murder attempt failed. Marta then vomits on him, revealing she had lied—Fran was already dead. Ransom has effectively confessed to murder in front of witnesses, and the police have recorded his statement.

In desperation, Ransom grabs a knife from Harlan’s display wall and lunges at Marta. To the shock of everyone present, the blade collapses harmlessly. The knife is revealed to be a retractable stage prop. Police officers subdue Ransom and place him under arrest.

Justice and Resolution

With Ransom taken away, Blanc reflects on the case. He admits that he suspected Marta from early on, noticing a drop of blood on her shoe. Yet her honesty and compassion thwarted Ransom’s elaborate plot. Blanc praises her ethical choices, which preserved her innocence even when the circumstances seemed damning.

As dawn breaks over the estate, the Thrombey family gathers outside, shocked and defeated. Marta stands on the balcony of what is now her home, sipping from Harlan’s coffee mug. The inscription reads, “My house, my rules, my coffee,” symbolizing the final transfer of power. The once-entitled family stares upward at the woman they had underestimated, while Marta watches them with quiet strength.