The Breach was cosmic anomaly created by the Precursors. In 2013, the Precursors created the Breach with the express intention of allowing the Kaiju to terraform the Earth for colonization. In 2035, ten years following the end of the Kaiju Wars, the Precursors attempted to recreate the Breach on a massive scale to continue their colonization efforts.
The original Breach
The original Breach was a fissure-like portal that resided off the coastline of China, near Guam. Transdimensional in nature, the Breach was created on floor of the Challenger Deep in the Pacific Ocean. The Breach connected the dimension of the Anteverse to Earth’s dimension, and manifested as a physical throat-like structure that expended large quantities of energy that would allow the Kaiju forced entry into Earth’s dimension from the Challenger Deep.
The Breach was designed in such a way by the Precursors that no physical or direct attacks could harm the portal. Nothing not of Kaiju or Anteverse origin could enter the Breach. The Breach was at its most vulnerable when Kaiju would exit or enter the Breach. If a Kaiju could be compromised, its DNA could be used to bypass its defenses.
Through information gained through his connection with the Precursors, Newton Geiszler was able to create a power core for Drone Jaegers infused with Kaiju DNA, strong enough for a unit of drones to not only recreate the Breach, but do so in such a way that multiple Breaches could be replicated at once.
So long as the drone hybrids maintained a steady power output from their power cores, the artificial Breaches would remain open long enough to allow Kaiju entry from the Anteverse onto Earth. Shutdown of the drone hybrids would cause the Breaches to collapse and close.
Kaiju Wars (2013-2025)
The original Breach was presumably created August 10, 2013. Several months prior to its opening, seismic activity was reported in the area of the Marinas Trench, but little understood what it meant. When the first Kaiju, Trespasser, emerged from the Breach, it triggered a twelve year war centered on the preservation of the Pacific Rim against the invading Kaiju.
The Pan Pacific Defense Corps' initial attempts to destroy the Breach with direct attacks were failures. Explosives and bombardment “bounced off” the portal and eventually, all attempts to directly attack the Breach ceased. Following the decline of the PPDC in 2025, the remnants of K-Science division eventually devised a plan use nuclear ordnance to destroy the Breach from within. The Battle of the Breach saw the employment of Striker Eureka and Gipsy Danger against the Category IV Kaiju Raiju, and Scunner, and the Category V Slattern.
When Striker Eureka, armed with the nuclear payload, was damaged and cornered by the Kaiju, it armed the payload in an attempt to destroy the Kaiju defending the Breach. Gipsy Danger was eventually forced to use Slattern, the only surviving Kaiju from the blast, to enter the Breach. The self-destruction of Gipsy Danger by Raleigh Becket, saw to the destruction of the Breach and the temporary safeguard of Earth.
Reemergence of the Kaiju (2035)
Unbeknownst to mankind, who would later assume that the Precursors created the Breach with the intention of destroying major city populations, the Precursors created the Breach and programmed the Kaiju to head for Mount Fuji. There, the Kaiju would commit suicide by jumping into the volcano. Their blood would react to the "rare Earth minerals" of the volcano and destabilize the Ring of Fire, triggering a planet wide extinction event that would kill all life on Earth, allowing the Precursors free reign to colonize the Earth.
Newton Geiszler, under the control of the Precursors, designed and manipulated the unmanned Drone Jaegers created by Liwen Shao, for the express purpose of helping the Precursors reenter Earth’s dimension. Following the fabrication of events that led to the death of Secretary-General Mako Mori, Shao’s Drones were approved by the PPDC, and situated across several Shatterdome locations on the Pacific Rim.
Dropping the ruse, Newton activated dormant Kaiju DNA that allowed him to override Shao Industries control of the drones. The hybrid drones began working in a unit and opening multiple Breaches across the Pacific Rim. Hermann Gotlieb and Shao were able to regain control of the drones, shutting them down and closing the Breaches. However, while their attempt was short lived, resulting in the death of at least one Kaiju, three Kaiju --- Shrikethorn, Hakuja, and Raijin --- were able to enter and began moving toward Mount Fuji.
In the aftermath of the battle with Mega-Kaiju, Jake Pentecost announced to an imprisoned Newton Geiszler that the PPDC prepared to invade the Anteverse, presumably using their own artificial Breaches.
- In a deleted scene of Pacific Rim: Uprising described by Steven S. DeKnight, Mako Mori explains to her brother Jake Pentecost that both she and Raleigh Becket were diagnosed with cancer after entering the Breach, explicitly stating that the Breach is atomic in nature.