Published August 23, 2007

The war has come to a climax — the Flood continue to grow in numbers and strength, the armies of Earth are scattered and decimated, and the Covenant threaten to activate the Halo, effectively destroying all life in the galaxy. Master Chief's mission is to stop the Covenant, destroy the impending Flood threat and ultimately save mankind. Here are some of the characters you'll encounter during this epic conflict.

Spartan 117 Master Chief
A tenacious, driven soldier, known primarily by his rank, the Master Chief is the last of the Spartan II soldiers. An elite group of genetically superior, highly trained super-soldiers, Spartans stand nearly seven feet tall, and in Mark VI Mjolnir powered assault armor, weigh almost 1000 pounds. Spartan 117 is expert in all weapon and combat systems, can run faster, jump higher, and hit harder than any normal human. He is the perfect weapon, honed by years of battlefield experience and has an unparalleled natural talent for war. He is our last and best hope.

The Arbiter
The disgraced Commander of the Covenant Fleet of Particular Justice was stripped of his rank and privilege and forced to don the ancient Armor of The Arbiter—a traditional Elite custom, where a warrior is sent on a final suicide mission to reclaim lost honor in death. In the pursuit of this mission, the Arbiter discovered that the Covenant's Great Journey was a lie, and he subsequently led a rebellion—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. It is a strange and strained alliance.

Cortana
The UNSC's most sophisticated A.I., Cortana is the onetime shipboard intelligence of the Halcyon-class cruiser, The Pillar of Autumn. Cortana, like most UNSC artificial intelligences, represents herself in holographic form when communing with her human colleagues. After helping destroy the first Halo by downloading herself into the Master Chief's armor, she formed a closer bond with him—but was wrenched apart by events on the second Halo. Her last known location was aboard the Flood-infested Covenant capital ship, High Charity, in the thrall of the Flood hive intelligence—the Gravemind. Cortana is the only link to the incredible secret of Halo—and if she cannot be saved, the Galaxy will fall with her.

The Prophet of Truth
The deluded and possibly insane leader of the entire Covenant civilization, this demented pontiff is leading his civilization down a suicidal path. He intends to activate the Halo array at any and all costs, and is happy to sacrifice his culture to do so, secure in his knowledge that he and his immediate cronies will be safe. The Prophet believes that he can follow the Forerunners to their mysterious final destination, and there, share their ancient and unlimited power. He literally believes that activating the Halo array will secure a path to Godhood. And he knows that the secret to this power may lie in the ancient sands of Earth.

The Gravemind
The virulent Flood organism spreads by murdering and absorbing sentient creatures. When it 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, and the deluded obsessions of the Prophet of Truth. The Gravemind intends to achieve its ultimate purpose—to consume and absorb every thinking creature in the Galaxy. The Gravemind has escaped the shackles of its Halo prison, and now roams free in the Covenant city-ship, High Charity.

Sgt. Major Avery Johnson
The battle-hardened Sergeant is the longtime cohort of the Master Chief. He's an excellent soldier and unmatched marksman who's seen more than his fair share of combat, and internal UNSC military intrigue. No other human knows the Master Chief as well as this capable and brilliant marine. Sgt. Johnson is that most singular of soldiers—a professional who's never more at home than in the thick of battle, and a loyal, fearless warrior who will do anything for his men, and his homeworld.

Commander Miranda Keyes
The daughter of the late Captain Jacob Keyes, Miranda Keyes now finds herself the Commander of Earth's tattered, broken ground forces. The Commander proved her worth and her mettle by following, and then helping assassinate the Prophet of Regret at the second Halo. Now, effectively leading a guerilla army against the marauding Covenant occupation force, Miranda must pull together a fighting unit with the weaponry, personnel and supplies that survived the devastation of the Covenant invasion.