Gargantua

Marine biologist Jack Ellway studies how seismic activity affects marine life around the island of Malau. A string of drownings interrupts the project and raises concerns about a hidden danger beneath the waves. The research team begins to suspect a mutated predator living in a nearby underwater trench.

While investigating, Jack and colleagues learn that a nearby underwater trench is home to a family of giant amphibians. They appear mutated after prolonged exposure to buried pesticides, linking the drownings to a dangerous new predator. The discovery shifts the project from observation to urgent study and containment.

A military presence lands on the island to assess the threat and support the scientists. Tensions rise between the researchers and the soldiers as the scope of danger becomes clearer. The island's security suddenly rests on more than just ecological concerns.

Jack's son Brandon befriends a baby amphibian that can venture onto land. The unlikely bond introduces a glimmer of hope for coexistence, but also signals the danger the creatures pose to humans. The discovery expands the stakes for the team and family.

A larger, bear-sized member of the family roams ashore and begins causing incidents on the beach. The threat grows quickly as panic spreads among locals and soldiers alike. The creature is eventually captured, raising questions about how to handle them safely.

While the younger creatures are held captive, their cries trigger the adult female’s vigil from the deep. The mother rises and begins a determined reclaiming of her offspring. The situation tightens as the family unit becomes a targeted threat to the island.

A plan to lure the mother back to sea by releasing the younger creature goes awry when a greedy fisherman tries to kidnap the juvenile for a payday. The scheme backfires, and the mother intensifies her search for her children. The island braces for further conflict under this new pressure.

Fearful for the safety of the island and his men, Colonel Wayne orders a military strike against the creatures. The brutal action ends with the mother being killed, marking a turning point in the crisis. The island's defense collaborates with scientists to salvage the remaining juveniles.

Brandon reveals the existence of the baby creature to his father, prompting a new plan to ensure the juveniles' safety. The remorseful Colonel Wayne buys them time to execute the plan, buying space for a potential escape back to the deeper waters. The family and scientists align on a risky course of action.

An adult male, mate of the slain female, arrives to reclaim his offspring and mourned mate. The confrontation escalates as the family and soldiers prepare for further danger. A sense of imminent threat underscores the urgency of keeping the juveniles safe.

Brandon and Jack manage to free the two juveniles from captivity. The newly reunited family pair with their recovered parent as the trio prepares to return to the deep sea. The rescue marks a hopeful turn in a brutal sequence of events.

All three remaining creatures depart back to the deep sea, escaping the island's immediate danger. The Ellways bid farewell to the illusion of safety as the creatures disappear beneath the waves. The island is left with the aftermath of the encounter and the promise of a fragile balance restored.