Halo 3‘s storyline was revealed by Bungie on the official site (along with the return of the M6D pistol). If you want to be completely surprised by the FPS game’s singleplayer campaign, then don’t read it, because it does contain spoilers of key plot points about the Humans, Elites, Covenant, and Flood. The following story bridges the events from Halo 2 leading up to Halo 3 come fall 2007.
The story so far… It is the year 2552.
Humanity has long been at war with the terrifying alien civilization that collectively calls itself the Covenant. This monstrous conglomerate of warlike species sees Humanity (1) as a form of heresy against their religion – a faith based in the single minded belief that a Great Journey awaits its faithful.
Unfortunately for the galaxy, this “Great Journey” must begin with the firing of a series of ring-like weapons scattered throughout space. These vast, terraformed rings are called Halos and have been long abandoned by their mysterious ancient creators, the Forerunners.
This conflict, terrible and destructive though it is, has been complicated by a series of cascading events. One of these artificial worlds, these Halos, was discovered and subsequently destroyed by Human forces. Led by the last fighting member of the legendary Spartan II military program, Spartan 117 – the Master Chief (2), a small band of soldiers managed to defy the Covenant and obliterate the Halo installation…
…A clash at a second Halo installation became a galaxy-spanning catalyst for destruction as civil war erupted within the Covenant. Driven by revelations that the Covenant leadership, the Prophets (3), had been deliberately deceiving its populace for millennia, the Covenant entered into a brief and complex civil war, and formed new alliances within its rank. The final result of that conflagration was that the Elites (4) now find themselves allied with humanity.
The truth was these Halos would not take the Covenant on a Great Journey, but rather eradicate all sentient life in the Galaxy. The cataclysmic structures were built by the ancient Forerunners as a last resort defense against the most terrifying menace the Galaxy has ever known – a menace the deluded Covenant has reawakened for the second time in a hundred thousand years.
That horror is the Flood (5), a sentient all-consuming parasite that makes monstrous puppets of those it kills. The Flood will not stop until every last thinking creature is absorbed into its ferocious intelligent plan.
Now, the second Halo has been activated, putting all of the remaining installations in a dangerous state of emergency standby – they are primed to fire.
Worse still, the Covenant has discovered the long-hidden location of Earth. They have crushed almost all human resistance as they seek vital clues to the nature of the Halo array – some of which may have been hidden under our very feet for until millennia.
Even with our newfound allies, the Elites, and their valiant and honorable leader, the Arbiter (6), we are still hopelessly outnumbered and at the mercy of the will of the Prophets, and the single minded force of the Flood.
With time running out, all hopes for the Galaxy now lie in the hands of the one soldier, Spartan 117 – the Master Chief. Finish The Fight!
(1) Species; Humans. Currently structured under the UNSC (a military command government), Humans find themselves damaged after years of fighting against the Covenant, Primarily a peaceful, exploratory species, Humans have attempted several diplomatic outreaches in this conflict, all ignored. Human occupied worlds have been destroyed and the current population has dwindled to almost nothing. Earth is currently being occupied by a Covenant archaeological/military force.
(2) Human (augmented); Master Chief. The Master Chief (real name John-117) is the last of the Spartan II warriors – an elite group of genetically superior, highly trained super-soldiers.
Spartan 117 is expert in all weapon and combat systems. He can run faster, jump higher and hit harder than any normal human. He is the perfect weapon, honed by years of battlefield experience and possessing a natural talent for war, unmatched by anyone left alive. He is our last and best hope.
(3) Species; Prophets. The religious and political leaders of the Covenant, Prophets are an elite class of bureaucrats. The theology that they apply to the Covenant species is based on the belief that firing the Halo array will herald, and indeed instigate a “Great Journey” which they appear to believe will result in some kind of sublimation event.
Physically frail, the Prophets wield power through absolute command of Covenant (and scavenged) technology.
Prophet; The Prophet of Truth. The deluded, and possibly insane leader of the entire Covenant civilization, this pontiff is leading his followers down a suicidal path.
The Prophet of Truth intends to activate the Halo array at any cost, and his happy to sacrifice his culture to do so. The Prophet fully believes that he can follow the Forerunners to their mysterious final destination and share their ancient and unlimited power. The Prophet also knows that the secret to this power may lie in the ancient sands of Earth.
(4) Species; Elites. Formerly the ruling military class of the Covenant, the Elites are proud storied fighters with a long and interesting history. Their recent split from the Covenant is based on differences in religious interpretation of the “Great Journey” but the schism runs deeper than that. The Elites have allied with their former Human foes in part because of a deep-seated resentment of the Prophet rule and in part because they actually understand the scale of the Flood problem.
(5) Species; The Flood. The Flood (sometimes called The Parasite by The Covenant) is a virulent, parasitic lifeform that thrives by consuming other sentient life of sufficient biomass.
The Flood appears in three primary forms: Infection, Combat, and Carrier, but also can evolve into the ‘Gravemind’ form that appears to act as a kind of hive-mind for the entire species. All of these forms have an attraction to any calcium-based life form of sufficient mass to accommodate them and will try to attack/infect any they encounter.
The Flood; Gravemind. When the virulent Flood organism reaches a certain critical mass, it develops a centralized intelligence, which calls itself a Gravemind. This is the Flood personified, and it carries with it the genetic memory of millennia of slumber.
The thing was stopped once before by the Forerunner activation of the Halo weapon, but it will not be stopped this time by a weak alliance of ruined humanity or the deluded obsessions of the Prophet of Truth. The Gravemind intends to achieve its ultimate purpose – consume and absorb every thinking creature in the Galaxy.
(6) Elite; The Arbiter. This disgraced Covenant Commander was stripped of his rank and privilege and forced to don the ancient Armor of The Arbiter. Following this traditional Elite custom, a warrior is sent on a final suicide mission to claim great honor in death.
In the pursuit of this mission, the Arbiter discovered that the Covenant’s Great Journey was a lie, and subsequently began a civil war that has shaken the foundations of the Covenant. The Arbiter’s people, the Elites, have joined humanity’s struggle against the rest of the Covenant.