The film opens on a mysterious island where a woman named Sloane Maddison, portrayed by Portia Doubleday, flees from unseen pursuers. Desperate to escape, she reaches out to the island’s enigmatic owner, Mr. Roarke, for assistance. However, he reminds her that she is merely a guest, and Sloane ultimately gets captured by her assailants.
Soon after, a plane lands on Fantasy Island, carrying an eclectic group of guests greeted by Roarke and his assistant Julia, played by Parisa Fitz-Henley. Among these new arrivals are Gwen Olsen, played by Maggie Q, Melanie Cole, portrayed by Lucy Hale, along with Patrick Sullivan (Austin Stowell), and stepbrothers JD (Ryan Hansen) and Brax Weaver (Jimmy O. Yang). Roarke informs them that their deepest desires can all be realized, but warns they must eventually reach their “natural conclusion.” Unknown to the guests, a man named Damon (Michael Rooker) watches intently from a distance.
As the guests begin to bond, Roarke starts fulfilling their fantasies. He brings JD and Brax into a world of endless partying, allowing JD to mingle with beautiful women while Brax enjoys an abundance of attractive men and recreational substances. However, Brax is soon confronted by a disturbing vision of a horrifically burnt man.
The next morning, Gwen converses with Roarke, who probes her about her past. Consequently, she is thrust into her own fantasy—a restaurant scene where she had previously declined a marriage proposal from her ex-boyfriend, Alan (Robbie Jones). Much to her surprise, Alan appears alive, having been ensnared in this fantasy too. As they reconnect, he proposes once more, and Gwen decides to accept his offer.
Meanwhile, Melanie confides in Patrick about her desire to terrorize her former school bully. Roarke leads her to a basement where she discovers Sloane, bound and vulnerable behind a two-way mirror. Believing it to be a mere hologram, Melanie takes pleasure in torturing Sloane by dousing her with toilet water and broadcasting a video of her infidelity to Sloane's husband. The situation escalates as Melanie realizes Sloane's true peril when a menacing figure resembling a doctor, whom she nicknamed Dr. Torture (Ian Roberts), appears with a buzzsaw. In a moment of redemption, Melanie uses a cattle prod to incapacitate Dr. Torture, freeing Sloane from her bonds while feigning ignorance about her earlier torment.
Then, Patrick is sent into a war-themed fantasy where he reunites with his father (Mike Vogel), who had died in action. As the plot unfolds, Patrick finds himself captured by soldiers, while JD and Brax recklessly explore their mansion filled with weapons, unwittingly triggering a firefight that spirals into chaos.
Sloane and Melanie, facing danger in the dark woods, encounter Dr. Torture once again, but are rescued by Damon. He reveals that he had come to the island seeking to meet his deceased daughter, but what was once a fantasy turned into a nightmare. Damon explains that the source of the fantasies is a magical water spiked in the guests' drinks by Roarke. The two women resolve to escape by reaching a phone while collecting some of the magic water for themselves.
As the narrative unfolds, tensions rise when another character, Mr. Sullivan, approaches Patrick, exposing a photo from Patrick's belongings, which reveals a painful history between them.
Gwen’s fantasy takes a drastic turn when she awakens to find herself married to Alan with a daughter named Lila (Jeriya Benn). Struggling to reconcile this unintended turn of events with her original wishes, she pleads with Roarke for a chance to change her fantasy. This plea spurs him to reflect on his own fantasies tied to his deceased wife.
The chaos continues as JD and Brax try to outsmart thugs demanding money in the mansion, while the narrative builds to a climactic confrontation among the guests. They realize that they are all intertwined in a tragic event involving a man named Nick who perished in a fire—an incident tied to each of their fantasies.
In their effort to escape, they confront Roarke and the darker truth of their desires inside the cave that houses the fountain of their fantasies. Each guest battles their personal demons, leading to revelations about their shared pasts. It becomes evident that they collectively bear responsibility for Nick's untimely demise.
The tension peaks when Roarke decides to assist the guests, ultimately making the choice to sacrifice his own longing to be with his late wife for their chance at escape. Each character must confront their true selves amidst the chaos of the fantasies that ensnared them.
As the climax unfolds, sacrifices are necessary, and several characters find themselves at a crossroads. The trio of Gwen, Sloane, and Brax awaken the next day, finally preparing to leave. Roarke reveals Brax’s unexpected choice, agreeing to stay on the island, ensuring JD can return home safely.
In the end, the interconnected stories speak to themes of regret, redemption, and the realization that our desires can have profound and sometimes haunting consequences.
