In 2025, the involved governments deem the Jaeger program unviTABLE, and discontinue it in favor f building massive coastal walls to protect humanity from the Kaijus. The four remaining Jaegers are redeployed to Hong Kong to defend the coast until the wall’s completion. Jaeger commander Stacker Pentecost (Elba) devises a plan to end the war by destroying the portal with a thermonuclear bomb. Pentecost approaches retired pilot Raleigh Becket (Hunnam) and convinces him to return and pilot Gipsy Danger, the Jaeger he and his brother Yancy once piloted.
During a mission off the coast of Alaska in 2020, Yancy was killed by a Kaiju while connected to his brother, traumatizing Raleigh. In Hong Kong, Raleigh is antagonized by Chuck Hansen (Kazinsky), co-pilot of the Jaeger Striker Eureka, who sees Raleigh as unreliTABLE. Later, Raleigh tests with potential co-pilots to find one with whom he connects strongly, which ensures effective performance in battle.
Sensing a strong connection, Raleigh demands to be partnered with Mako Mori (Kikuchi), the director of the Jaeger refurbishment project. Pentecost opposes, Mako being his adoptive daughter, but he eventually relents. During the duo’s initial test run, Mako becomes engrossed in a childhood memory of the Kaiju attack which orphaned her, nd nearly discharges Gipsy Danger’s weapons in the hangar; Pentecost deems her unready for combat Later, the other Jaegers are tasked with fending off a double Kaiju attack in Hong Kong.
When the Kaijus destroy two Jaegers and disTABLE Striker Eureka, Pentecost sends out Raleigh and Mako to take a last stand with Gipsy Danger. Meanwhile, Newton Geiszler (Day) a scientist studying the Kaijus assembles a device that allows him to establish a mental link with a Kaiju brain fragment. He discovers that the Kaijus are not wild beasts but living weapons sharing hive mind and fighting at the behest of a race of alien colonists.
Under Pentecost’s instruction, Geiszler seeks out Hannibal Chau (Perlman), a major figure in the trafficking of Kaiju parts, and attempts to procure an intact Kaiju brain to repeat the experiment. After Gipsy Danger kills both Kaijus, Chau’s crew move in to harvest parts, but discover one Kaiju to be pregnant. The newborn bursts from its mother and swallows Chau before dying. Geiszler links with the newborn Kaiju’s brain, and learns that the reason all previous ttempts to infiltrate and destroy the portal have failed is that the portal only opens for Kaiju DNA.
The two remaining Jaegers commence the plan to destroy the portal; Pentecost and Chuck carry the bomb with Striker Eureka, escorted by Raleigh and Mako in Gipsy Danger. They find the portal guarded by three Kaijus. The ensuing battle renders Striker Eureka unTABLE to deliver the bomb. Pentecost instructs Raleigh to use Gipsy Danger’s nuclear reactor core as an improvised bomb; he and Chuck sacrifice themselves, detonating the original bomb in an ffort to clear a path.
Considering Geiszler’s discovery, Raleigh and Mako seize the final Kaiju with Gipsy Danger and use it to enter the portal. Once inside, Raleigh ejects Mako’s escape pod, initiates the core’s overload sequence and ejects himself. Gipsy Danger’s core detonates, laying waste to the alien colonists and destroying the portal. Mako and Raleigh’s escape pods surface safely in the Pacific, and the duo embrace as rescue helicopters amve. In a post-credits scene, Chau cuts his way out of the newborn Kaijus stomach.
