Private detective Nick Bali, known as "The Jealousy Man" and portrayed by Joseph Gordon-Levitt, finds himself entwined in a web of family secrets on the picturesque Greek island of Crete. He is covertly enlisted by Shailene Woodley, who plays the desperate Penelope Vardakis, to uncover the truth behind the mysterious death of her husband Elias' identical twin brother, Leo, who is also played by Richard Madden. The official narrative claims it was a tragic climbing accident, but Penelope believes there's more lurking beneath the surface.
The Vardakis family, with their considerable wealth and influence, have effectively stifled any investigation, fearing that any scrutiny could damage their shipping empire. Penelope reveals her personal history with Leo, asserting that he was a genuinely good man whose life was unjustly cut short. "If I don't investigate the murder, then nobody will," she declares, as she arranges for Nick to stay in a nearby monastery.
Haunted by the ghosts of his own past—his broken marriage and memories of his daughter—Nick's coping mechanism involves an over-reliance on alcohol. He begins his investigation by examining the coroner's report on Leo, where he discovers inconsistencies that suggest Leo's injuries were not consistent with an accident from the cliff. Officer Georges Mensah, a character portrayed by Babou Ceesay, is the officer in charge, but when Nick approaches him, he faces resistance.
Nick then spots Elias leaving the family yacht, and he decides to confront him, posing as an investigator from the Greek National Intelligence Service. Their chat reveals tensions between the brothers fueled by a childhood steeped in competition, as Elias reluctantly admits to a fight with Leo before his death. However, their conversation is cut short when Elias becomes suspicious and abruptly departs.
Determined to dig deeper, Nick reaches out to Mensah once more, and they form an uneasy alliance. Penelope cautions him against engaging with the family, sensing that Elias harbors greater secrets. Nick learns about Elias's connections to a local fixer, Yannis, portrayed by Emmanouil Gavridakis, who supplies various illicit services to wealthy visitors.
During his investigation into Leo's life, Nick discovers that Leo had romantic feelings for Penelope, coupled with the unsettling revelation that their mother Audrey, played by Clare Holman, prevented him from taking a more significant role in the family business. Leo’s discontent only deepens with the knowledge that he was overshadowed by Elias, who received preferential treatment from their parents.
Together, Penelope and Nick visit the cliff where Leo met his tragic end, confirming its remote location only accessible by boat. She recounts the conflicted emotions of her past relationships with both brothers, revealing how Elias's manipulation led to a tangled love triangle.
Intrigued to understand if Leo posed any real threat to the family, Nick seeks a meeting with Audrey. With some clever maneuvering, Penelope secures Nick an invitation to a lavish event hosted by the Vardakis clan. Not one to back down, Nick attempts to confront Audrey about possible foul play, only to be violently expelled from the yacht.
After an unexpected altercation with Elias's henchmen, Nick manages to regroup with Mensah, who tends to his wounds. As Penelope confides in Nick about Elias's obsessive nature, he begins to piece together more about the family dynamics and the hidden truths surrounding Leo’s death.
Through a series of investigative breakthroughs, Nick pins down the boat used in Leo's demise and prepares for a confrontation. In a dramatic culmination of events, they track down the boat's location, leading to a violent encounter that results in the death of several alleged killers and leaves Mensah injured. Guilty and troubled, Nick contemplates the final pieces of this harrowing puzzle.
In a climactic gathering of characters, Nick unveils a shocking twist: Leo was not the innocent victim but had orchestrated Elias' tragic fate by breaking his fingers before sending him over the cliff. A distraught Audrey, in a fit of rage, kills Leo, while Penelope whispers her last words to him.
The tension finally subsides, but not before Penelope reveals her true intentions for hiring Nick. Initially hoping to find autonomy from her oppressive circumstances, she realizes that Leo’s motives were more sinister, as he aimed to take over the family business and keep her bound to him.
In this tension-filled drama, Penelope encourages Nick to confront his own demons and suggests he return to his daughter, leaving the island of secrets behind. The tale intricately weaves themes of loyalty, jealousy, and the lengths one will go for love and truth.
