Halo 2

Halo 2 is a first-person shooter developed by Bungie Studios for the Xbox video game console and is backwards-compatible with Xbox 360. It is the sequel to the game Halo: Combat Evolved and the prequel of Halo 3(september 2007), and features a newly built graphics engine with the addition of new elements to the game. This game was the best sealler of the Xbox console as well for all microsoft games.

The game further develops the struggle between the United Nations Space Command and the Covenant Empire. It take place in 2552.

First Battle of Earth
The game begins some mounths after the events of Halo: Combat Evolved. Before the game begins, we catch a small glimpse of the Covenant via a cutscene. For the first time, we learn a little bit about the society of the Covenant. A constrained and armorless Supreme Commander is being branded with the Mark of Shame. It is revealed that he is the former Supreme Commander of Fleet of Particular Justice. The Covenant fleet that destroyed Reach, as well as the one which failed to save Alpha Halo.

John-117 begins on Cairo Station, one of the three hundred space defense platforms orbiting Earth. Shortly after the Covenant arrive, a bomb is set on the station. After a while, Master Chief finds the bomb and uses it to destroy a Covenant assault-carrier. He and the Marines then set out to the city of New Mombasa as a sole surviving Covenant ship landed on Earth. While in the city, Master Chief destroys a Scarab. After the Scarab is destroyed, the Covenant ship makes a Slipspace jump which destroys the city, and the UNSC ship, In Amber Clad, with the Master Chief aboard, gets swept up in the warp field in a desperate attempt to follow it.

The Arbiter
The Elite branded in the opening cutscene was supposed to be executed; however, rather than have him slain outright, the Prophets of Truth and Mercy made the decision to give him a chance to regain his lost honor and serve the Covenant again.

The Prophet's offered him the role of Arbiter, the highest honor for an Elite during a time of need. As Arbiter, he must conduct missions for the prophets that are hopeless and suicidal and die as a martyr for his race. This is part of the Great Journey, which is a religious series of events that the Covenant heavily believes in. In order to complete their "Great Journey", the Covenant must activate a Halo installation. It is assumed that the "Great Journey" is referring to a space age rapture that will kill all life in the galaxy, and there will be a "Judgement Day" where all will be judged and the ones without sin will go to a heaven of some sort.

As his first mission as Arbiter, the Elite must eradicate a group of Heretics who have separated themselves from Covenant society. They reside in a gas facility near the destroyed Alpha Halo. The Arbiter was to die during this mission, but he narrowly escaped death and defeated the heretic leader. This is the first time we witness conflict within the Covenant society as the heretics constantly tell the Arbiter he is a fool for believing in their Great Journey and the lie of the Prophets.

Discovery of installation 05
During this time, Master Chief, aboard the ship UNSC In Amber Clad, is transported to the vicinity of another Halo ring - the Delta Halo - perhaps many tens of thousands of light years from Earth, on which they land. This time, Cortana and Master Chief are well aware of the dangers of Halo. They quickly begin to search for a way to disable it before the Covenant are able to reach it. Master Chief discovers the existence of the Prophet of Regret, and must infiltrate his temple and kill him. Rather than aiding, the Prophet of Truth calls back the Phantoms and destroys the temple with an Energy Projector. Narrowly escaping, Master Chief is then captured by Gravemind.

The Index and Gravemind
The Arbiter remains alive and is sent by the Prophets to Delta Halo. The Arbiter is sent to lower the contamination shields surrounding the Library so the Covenant ships may approach. It is revealed to the Covenant that the Flood have been released, however, the Covenant still press forward. After completing his mission and retrieving the Index, Brute Chieftain Tartarus takes the Index from The Arbiter. The Arbiter objects, saying the Prophets will not stand for his actions, to which Tartarus laughs, informing him that the Prophets sent him to kill Arbiter. Tartarus then throws the Arbiter into the seemingly bottomless core of the Library.

In the next cutscene, the Arbiter is caught in a green vine-looking object. He is next to Master Chief who has just regained consciousness. A giant being known as Gravemind, a form of the Flood, holds the two. He comments on the differences between Humans and Elites and informs the Arbiter of the Prophets replacing Elites with Brutes as they don't feel Elites can protect them any longer. He tells of their killings and then reveals that he has reanimated the corpse of the Prophet of Regret as part of himself. He also has with him 2401 Penitent Tangent, the monitor for Delta Halo. 2401 and Regret argue about the truth behind The Great Journey, Regret saying it will bring salvation while 2401 disagrees with the Covenant's responsibility in handling Halo and the Flood. Gravemind comments that the Covenant will not find the salvation they are looking for. He then transports both Master Chief and The Arbiter to places where they will likely find the Prophet of Truth who has the Index, which Gravemind wants back. It is now that the Arbiter realizes the Elites have been betrayed, and finds it hard to believe.

High Charity
Master Chief is transported to High Charity where he inputs Cortana into the Covenant network, separating himself from her. She discovers that the Covenant are in the middle of a civil war with the Prophets executing a genocide against Elites, feeling the Elites can not protect the Prophets. Brutes are put in their place and sent to wipe out the remaining Elites. As Master Chief travels through the holy planetoid, he encounters much conflict between Covenant, allowing for less resistance against himself, making it easier for him and Cortana to infiltrate the area. Their success leads to Prophets to promote this as a failing of the Elites rather than acknowledging their forces are scattered and unorganized.

When Master Chief reaches the other prophets (Truth and Mercy), he sees Sergeant Johnson and Miranda Keyes get captured and the Flood starts to attack. In the attack the Prophet of Mercy dies. After Master Chief gets close to the Forerunner ship, he tries to grab Cortana but can't because she does not want to risk a remote detonation of In Amber Clad so she stays on and becomes separated from the Master Chief and is left within a computer on High Charity.

The Schism
The Arbiter is transported to a forest and finally realizes the truth in Gravemind's words after being attacked by a group of Brutes, who were once his allies. He rallies Elites and makes his way to the entrance of the structure. Once making his way through the cavern, he reunites with Rtas 'Vadumee, an Elite Commander. They combine forces with Sergeant Johnson and help get the Scarab to the middle structure to make an entrance for the Arbiter to get to Tartarus. He then makes his way to the center of the structure to stop Tartarus from activating the ring.

The Halos, we learn from 343 Guilty Spark, were built to prevent the Flood from spreading throughout the Galaxy, and that the Forerunners who built it were wiped out when they fired it as a "weapon of last resort" at some point in the remote past. In spite of this, the Brute leader Tartarus forces Miranda to activate the ring in preparation to fire, to bring about - in his eyes - the Great Journey. The player must fight Tartarus(and on higher levels other brutes) to retrieve the Index and stop the activation of Installation 05.

The Index is retrieved and the Installation cannot fire. 343 Guilty Spark reveals that although the Index was removed before Delta Halo had time to complete it's firing sequence, it sent signals to other Installations in the Galaxy, putting them on standby mode. Now, they can be activated remotely from the Ark.

After that scene the camera moves to a picture of Master Chief apparently aboard the Forerunner ship. When asked why he is on the ship all he says is, "Sir, finishing this fight."

After the credits roll, a teaser for Halo 3 shows where the Flood has completely taken over High Charity with the Gravemind saying "Silence fills the empty grave now that I am gone, but my mind is not at rest, for questions linger on." The scene then changes to a stand in the council chambers of the Hierarchs the Gravemind then says "Now I shall ask, and you shall answer." It then changes to Cortana saying "Alright, shoot".

There is no novelization of this game yet. It is possible that a novelization that follows the canon laid down by the previous three novels might differ somewhat plotwise from the game, due to various differences between the game and the other novels.