Pleasure Island is a dazzling yet deadly resort situated off the coast of Costa Rica, owned by the renowned musician Coconut Pete. The seemingly idyllic setting quickly unravels when staff members Rolo, Stacy, and Kelly sneak into the jungle for a romantic rendezvous, only to face a horrifying ambush by a masked killer who mercilessly stabs Rolo.
As tensions escalate, the killer relentlessly hunts down the girls, pushing Kelly off a cliff and decapitating Stacy before she can reach safety. The resort staff remains blissfully ignorant of the ongoing horrors until the gruesome discovery of Carlos' body behind the kitchen triggers alarm. Dave recounts a chilling tale of a former employee who succumbed to madness and slaughtered his co-workers; however, Pete dismisses it as a mere campfire myth meant to provoke fear in the guests. Despite his reassurances, the rising body count paints a more sinister picture.
When Putman stumbles across the lifeless body of Cliff in a hedge maze, panic grips the resort. A menacing message from the killer reveals a targeted attack on the staff, while communication devices and transportation are mysteriously disabled. Hank, a former FBI agent, persuades the staff to stay vigilant and continue their duties, vowing to apprehend the elusive murderer. Meanwhile, Yu seems determined to alert the guests to the lurking danger, despite receiving dire warnings from the killer. Her attempt to gather the guests on the beach ends in tragedy when her arms are severed in a brutal assault, and Hank meets a grim fate as he tries to intervene.
Doubt starts to cloud the staff's judgment as they turn their suspicion towards the guest Penelope. Juan, believing in her innocence, attempts to clear her name. As the tension rises, Putman disappears into the jungle plagued by nightmares.
Sam and Dave make a startling discovery—a shrine decorated with photos of Lars and the guests reveals disturbing alterations that suggest a sinister connection. With the resort's eerie atmosphere thickening, they mistakenly implicate Lars and confine him to a room for safety. The killer cuts the power, invoking chaos, and when Pete’s body is found, the staff turns against one another. Amid the turmoil, Jenny insists that they must unite to survive until help arrives, yet they splinter into smaller, vulnerable groups.
As Dave manages to restore power, Jenny and Lars are drawn by music to the electricity hut, only to be confronted with the horrifying sight of Dave's severed head. Following the escalating bloodshed, during a nightclub party, the remaining staff members find the bodies of Dave and Putman, triggering mass panic among the guests.
Amid the chaos, Sam's previously thought-dead body springs to life from a mud bath, wielding a machete and seizing control. He reveals himself as the mastermind behind the killings, driven by jealousy and a twisted motive to prevent Pete from selling the island. In a desperate clash, Lars manages to thwart Sam’s plans, leading to a chaotic struggle for survival.
During a frenzied chase, Juan, Jenny, and Penelope barricade themselves in the nightclub but soon witness the horrifying sight of Sam attempting to drown Penelope in a tank. As Juan smashes the tank to rescue her, Sam’s bloodlust turns their sanctuary into a treacherous battleground. In a climactic showdown, Lars finally manages to stab Sam, yet not without cost.
The fight for survival culminates on a cliff's edge as the survivors—Lars, Jenny, and Penelope—make a desperate leap into the ocean. In the aftermath, they scavenge the resort's damaged boats, aiming for escape, only to be hunted down one last time by the merciless Sam, who is horrifically bisected by a boat propeller. Despite their dire circumstances, the trio powers on, racing away into the uncertain horizon as the nightmares of Pleasure Island continue to pursue them.
