Piranha

David and Barbara, adventurous backpackers, stumble upon what they believe to be an abandoned military outpost. Intrigued, they explore the area, not suspecting the horrors that await them deep within.

The couple finds a vast, man-made reservoir nearby and decides to indulge in some skinny dipping. Their innocent fun quickly turns into a terrifying ordeal as they are suddenly attacked by an unknown underwater entity.

Maggie, hired by Barbara's parents, embarks on a mission to uncover the fate of the missing couple. Armed with funding from her boss Earl, she makes her way to the remote mountainous area where they were last seen.

Upon arrival, Maggie seeks out Paul Grogan, a rugged survivalist living in a log cabin. Together, they set off to investigate the military facility as Maggie hopes to find clues about David and Barbara's disappearance.

As they reach the military complex, Paul notices something peculiar about the water—it has a salty quality. This leads them to delve deeper into the mysteries surrounding the facility and its past experiments.

While exploring the complex, they come across a laboratory filled with bizarre, mutated creatures, including a terrifying lizard-like beast. This revelation heightens their concern over what possible threats may be lurking in the water.

Maggie theorizes that David and Barbara could have drowned in the pond, leading her to decide to drain it for further investigation. However, chaos ensues when an elderly man appears, desperate to stop her.

After draining the pond, Maggie and Paul are horrified to find the skeletal remains of David and Barbara caught in the drain. This grim discovery solidifies the threat lurking in the water and intensifies their mission.

The injured man they rescued reveals himself to be Dr. Hoak, a former military scientist responsible for the mutant piranha project. He explains the horrifying truth about the genetically modified species intended for warfare and his continued experiments.

The mutant piranha begin their deadly rampage, resulting in a series of gruesome attacks. Friends and families are caught unaware and suffer tragic fates as the fish attack relentlessly.

As the threat escalates, Paul and Maggie rush to warn a nearby summer camp where Paul's daughter, Suzie, is attending. Their pleas are dismissed, leaving them frustrated and anxious for her safety.

At the summer camp, chaos erupts as counselors struggle to keep the children safe from the attacking piranha. In a brave but heartbreaking moment, Suzie attempts to help but witnesses one of her counselors being devoured.

Racing against time, Paul and Maggie head toward a resort nearby, hoping to raise the alarm. The resort owner initially scoffs at their warnings, but soon they realize the danger is imminent.

As the piranhas launch a massive attack on the resort, panic and horror ensue among the guests. The scene turns chaotic with many casualties as the mutant fish wreak havoc.

In a climactic confrontation, Paul and Maggie attempt to thwart the piranha by contaminating their water source. Barely escaping with their lives, they reflect on the still-looming threat that might not yet be eradicated.