Mega Shark vs. Kolossus

In a Russian mine, Benedict's prospectors uncover a secret stock of red mercury. One member is revealed as American agent Moira King, raising tensions with the Russians. As they drill, the hidden mega-weapon Kolossus stirs beneath the surface and reawakens.

The standoff between King and the Russians escalates as Kolossus emerges, a mobile WMD powered by red mercury. The mine is destroyed in the chaos as the robot rampages. The threat to regional security grows instantly.

Dr. Alison Gray proposes sonic transmitters to influence shark behavior, hoping for a humane solution. Her idea is rejected in favor of an aggressive plan. She is soon recruited by Joshua Dane who envisions another approach.

Dane reveals his infiltration of government communications and suggests working with Alison to stop the shark without broad environmental damage. They form a tentative alliance while pursuing a different strategy.

Moira King brings desk worker Spencer into the mission to assist in halting Kolossus. They assemble a small, capable team to track down the weapon and its creator.

Kolossus is identified as a mobile WMD from the Cold War, powered by red mercury and capable of multiple detonations. Its development and purpose are traced to a secret Russian program, alarming global defense planners.

Dane and Alison attempt to use Alison's transmitter aboard a hydrofoil to steer the shark, but the pod malfunctions and allows the creature to escape. The team regroups and resumes pursuit.

The group tracks Sergei Abramov, Kolossus' creator, who provides a compass and clues to where the weapon's control technology can be found. Abramov is killed by Kolossus during their confrontation.

Following Abramov's clues, the team reaches the underwater laboratory where Kolossus is operating. Admiral Jackson suffers a breakdown and orders a nuclear launch, but Parker overrides the order; an American flag is used to lure the shark into the inlet, trapping it near the laboratory.

The team searches the submerged lab for Kolossus' control device and engages in a brutal battle with the robot. They locate the device and escape just as the laboratory is crushed by the rampage.

Dane reveals that he was Benedict's sponsor and sabotages Alison's transmitter to prevent the government from killing the shark prematurely. He retrieves the red mercury and prepares a worldwide broadcast.

With the transmitter and red mercury in hand, Dane forces Kolossus to attach a transmitter to Mega Shark and broadcasts his plan worldwide. Governments scramble jets as they try to respond.

The US SDI satellite is activated in an attempt to neutralize the threat, but Kolossus disrupts the plan and drives the Mega Shark toward space. The transmitter falls off; the shark returns to the ocean and Dane is crushed when Kolossus attacks his ship.

Mega Shark and Kolossus engage in a brutal final duel. Kolossus drags the shark down and detonates its remaining red mercury, destroying both creatures. The survivors watch from shore as the sea calms and the crisis ends.

Deep underwater, a new Mega Shark egg hatches, signaling a renewed threat on the horizon. In a post-credits sting, Dr. Bullock is killed by the newly emerged Mega Shark.