|Developer(s): Guerrilla Games
Publisher(s): Sony Computer Entertainment
Platform(s): PlayStation 3
Release date(s): February 22, 2011
Genre(s): First-person shooter
Mode(s): Single-player, online multiplayer, offline split-screen co-op
The game begins in medias res from the point of view of (presumably) two Helghast soldiers who have arrived at Stahl Arms Corporation, Jorhan Stahl’s weapons factory. The two are taken to an execution room where the captured Jason Narville’s execution is about to be broadcast by Stahl across Helghan. As the two soldiers are about to execute Narville, they reveal themselves as Tomas “Sev” Sevchenko and Rico Velasquez and the scene cuts back six months earlier, immediately following the events of Killzone 2.
Sev and Rico regroup with Captain Jason Narville outside Scolar Visari’s palace and they begin their evacuation towards the remaining ISA ships on Helghan, facing heavy resistance from organised Helghast troops led by Admiral Orlock, whose plan is well-received by most of the senate except for Jorhan Stahl, the chairman of Stahl Arms, the largest weapons manufacturer on Helghan. From the outset, the animosity between the two parties is made apparent. Rico receives a transmission from Jammer and separates from the group to rescue her squad who have encountered heavy resistance. All the ISA ships depart or are destroyed by the Helghast, leaving Sev and the rest of the ISA forces marooned on Helghan.
Jumping six months forward, the Helghast senate express their disappointment with Orlock’s search for the remaining ISA forces, having initially promised that they would be dead within the hour. As a result, Stahl refuses to hand over his weapon prototype to the military, citing the Admiral as incompetent. Stahl organizes his private army to hunt down the ISA who are hiding in a Helghast jungle. Narville dispatches Sev along with a soldier named Kowalski to retrieve a satellite uplink in order to contact the Vektan government. Upon doing so, Earth Command informs Sev and Narville that the ISA has surrendered and that they are to surrender. The Helghast soon track the ISA in the jungle, ending with their capture and the death of Kowalski.
Rico, and his men including Jammer, who have been separated from the main group for six months, are able to rescue Sev, who convinces them to save Narville and the rest of the captured ISA forces. They track them to Stahl’s base and discover a horrifying new weapon using irradiated Petrusite, a compound that causes victims to explode. Disguised as Narville’s executioners, Sev and Rico rescue Narville in addition to freeing some of their men held as prisoners of war and used as test subjects for Stahl’s new weapons. On their way out, Rico and Sev discover Stahl’s plan to destroy Earth and the ISA chase Stahl’s cruiser to the Helghast orbital elevator.
Embarrassed by Stahl’s failure to execute Narville, Stahl is ordered to turn over his new weapons to the Helghast military by Orlock, who has now become Helghan’s dictator (Autarch). He is made to meet with Orlock at the space station where he plans to kill Stahl. The remaining ISA soldiers arrive at the orbital elevator and ride up to the space station to stop Stahl from attacking Earth. Stahl turns on Orlock, murdering him after a brief fight, and makes preparations to bombard Earth. The remaining ISA forces hijack two fighters and Sev manages to shoot down Stahl’s cruiser. Unwilling to let Stahl escape the cruiser, he drops a nuke on the falling cruiser, releasing massive amounts of Petrusite into Helghan’s atmosphere. The Petrusite engulfs the entire planet and wipes out everything on its surface. Jammer then reports that Helghan has gone dark and Sev contemplates on the many lives on the planet obliterated by the Petrusite.
In a mid-credits scene, two Helghast soldiers are searching through some ruins when they come across an escape pod. Though the occupant’s identity is not revealed, both soldiers bow and say, “Welcome home sir.”, heavily implying that Stahl survived and managed to escape his cruiser before it was destroyed.