Terracide

"The war between the Vektans and the Helghast ended in seconds. They call it The Terracide. A billion lives lost in the petrusite fires that swept Helghan's surface, reducing it to nothing more than a lifeless rock."

―Echo

The Terracide was the planetary devastation of Helghan that occurred during the end of the Second Extrasolar War on May 2360.

Background

Near the end of the Second Extrasolar War and following Scolar Visari's death at the hands of the Interplanetary Strategic Alliance during Operation Archangel, two Helghast leaders - arms manufacturer Jorhan Stahl and Admiral Orlock - aimed to succeed Visari, each coveting the position of Autarch.

Both Stahl and Orlock had extensive military resources and political backing, and their contention for power and their bitter rivalry escalated into a brief civil war. After having Orlock dealt with, Stahl arranged for his experimental attack vessel, the Khage, which was carrying irradiated petrusite missiles from Pyrrhus, to launch a direct attack on Earth, the capital world of the United Colonial Nations, in an effort to cow the UCN's colonies into surrendering to his rule.

Following Orlock's death, remnants of the ISA invaders enter the conflict between Stahl's military and the Helghast loyal to Orlock. In an effort to vanquish Stahl, ISA operatives commandeered a pair of Strike Fighters and chased Stahl across the battle to the Khage. Eventually, Tomas Sevchenko launched a nuclear missile from his Strike Fighter towards the Khage, destroying it. However, the impact caused the unintended detonation of the Khage's irradiated petrusite warheads in Helghan's atmosphere, causing a chain reaction of petrusite irradiation to destroy the Helghast fleets and incinerating the surface of the planet.

Detonation

"I'm not hearing any comm traffic."
"We took out the whole fleet."
"I mean nothing. The entire planet is silent."

―Jammer and Rico

The Helghast face extinction.

Enormous petrusite fires ignited as a result of the missiles, and propagated rapidly throughout the planet, engulfing Helghan in a wave of nuclear fire. The irradiated petrusite missiles used in Stahl's cruiser, combined with nuclear weapons and Helghan's high levels of radiation, fueled a large-scale chemical combustion. The resulting detonation caused tremendous damage to both organic life and inorganic structures such as vehicles and buildings.

In general, Helghan's civilian population had no inkling of the oncoming disaster or at what time it would strike, and to many it was to be an ordinary day. Many people who were far enough away from the petrusite fires not to be killed on impact, were killed by the collapse of buildings or fallen debris. The death toll resulting from the detonation and its immediate aftermath was estimated at one billion.

Effects

"Jesus, how many people were down there?"

―Tomas Sevchenko

Damage from the detonation left large portions of the planet uninhabitable and largely unsafe, particularly because of subterranean tremors. These tremors echoed long after the blast and continued to stimulate large buildings and city structures to collapse. Despite this, there were a number of survivors. The civilians who survived migrated in large numbers toward the less affected zones, establishing temporary shelters and makeshift hospitals. At one of these hospitals, future Black Hand leader Vladko Tyran was said to have been born.

The remnants of the Helghast government provided cruisers for use as escape vessels for the survivors and moved many of them off of the planet. However, some civilians could not be transported, either because the vessels were at full capacity or because they could not reach the evacuation site quickly enough. In particular this was an issue with elderly people and small children. Civilians in this category remained in Helghan.

Meanwhile rumors began to circulate that Jorhan Stahl was still alive somewhere on Helghan.

Aftermath

Helghast ships evacuating Helghan.

Ruined buildings of Pyrrhus.

Overlooking remnants of Pyrrhus

The devastated Helghan military corps regrouped its resources and remained active. Those that were evacuated from Helghan were offered refuge on Vekta by the ISA after an uneasy truce was negotiated, allowing them to colonize half of the planet and established New Helghan, the successor state of the Helghan Empire. Others have also taken residence on the planet Gyre.

Despite the eradication of all major settlements, a number of corporations continue to use the planet as a base of activities, resulting in a small, semi-permanent population. The most notable of these corporations is Stahl Arms (under a shell company name Dolarhyde Consortium), along with its own R&D personnel, and a connected military base. New Helghan continued to use petrusite imports as a power source and an economic commodity. This compelled the refineries on Helghan to remain active and staffed despite the hazards of extraction and the refineries' distance from most consumers.

Ruins from former settlements, such as the former Pyrrhus region, were numerous and remained strewn throughout the planet. Some regions remained fraught with automated attack drones and other combat automata, which were remnants of the Second Extrasolar War. There was a large concentration of drones adjacent to Stahl's base, which may have been a deliberate decision by Stahl. These remained engaged long after the evacuation to New Helghan, making it difficult for non-military groups to survey the area.

The Helghast blamed the cause of the Terracide on ISA soldiers Tomas Sevchenko and Ricardo Velasquez, who were responsible for detonating Stahl's cruiser, and labelled them as war criminals. Sevchenko and Velasquez were forced into hiding while the ISA claimed the two soldiers as "missing in action." The Helghast has since established a manhunt for the soldiers, who still remain uncaught.

Trivia

• Despite the Terracide in the ending of Killzone 3 showing irradiated green petrusite on the planet, in Killzone Shadow Fall the same event is shown with regular blue petrusite.