Halo 3

Story

After the events in the comic book adaptation Halo: Uprising, the Master Chief crashes in East Africa, where he is found by Johnson and the Arbiter. The Chief, Johnson and his companions fight the Covenant in the jungle and reach a UNSC outpost. Here, Keyes and Lord Hood plan a final attempt to prevent the Covenant leader, the High Prophet of Truth, from activating a Forerunner artifact found outside the ruins of the city of New Mombasa. The Chief clears Covenant's air defenses so Hood can lead Earth's last ships against the Prophet, but Truth activates the buried artifact and creates a slipspace portal into which he and his followers enter. A Flood-infested ship crashes nearby; elite troops arrive and gas the Flood-infested areas of Earth to stop the threat. Following a message left by Cortana aboard the Flood ship, the Chief, Arbiter, the Elite soldiers, Johnson, Keyes and their troops follow Truth through the portal. They are joined by 343 Guilty Spark, who assists the Chief since he has no mission to complete after the destruction of his Ringworld. On their journey through the portal, the humans and elites discover a huge artificial structure, the Ark, far beyond the Milky Way Galaxy. Here, Truth can activate all the halos remotely. The Flood come aboard the High Charity in full force and begin to infest the facility. Truth captures Johnson, needing a human to use the Forerunner's technology. Keyes is killed during a rescue attempt, and Johnson is forced to activate the rings. Gravemind makes a truce with the Chief and the Arbiter to stop Truth. The Arbiter, Master Chief, and Flood troops arrive, overpower Truth's guards, free Johnson, and prevent the activation of the rings. After the Arbiter kills Truth, Gravemind turns on the Chief and the Arbiter. The Chief, Arbiter and Guilty Spark discover that the Ark is building another Halo to replace the one the Chief destroyed earlier. The Chief decides to activate this halo. The Ringworld would eliminate the Flood plague on the Ark and save the entire galaxy from destruction. To activate the ring, the Chief rescues Cortana, who has the activation index of the destroyed halo, from High Charity and destroys the city. Once on the new halo, Cortana warns that Gravemind is trying to rebuild on the ring. The Chief, Arbiter and Johnson travel to Halo's control room to activate the ring. Guilty Spark explains that the ring is not yet complete and premature activation would destroy it and the Ark. When Johnson ignores his warning, Guilty Spark mortally wounds him to protect "his" ring. The Chief destroys Guilty Spark, activates the ring, and escapes the ring's self-destruct on the UNSC frigate Forward Unto Dawn. However, the force of Halo's explosion collapses the slipspace portal, leaving only the forward half of the Forward Unto Dawn to return to Earth with the Arbiter aboard. On Earth, a memorial service is held for the fallen heroes of the war between humans and the Covenant, with the Arbiter and Lord Hood speaking briefly about the fallen Master Chief. After the memorial service, the Arbiter and his elite brethren depart for their home planet of Sanghelios. Meanwhile, the back half of the Forward Unto Dawn drifts in uncharted space. Cortana sends a distress signal, but it may be many years before they are rescued. The Chief falls into a cryonic sleep and says to Cortana, "Wake me up if you need me." When the game is completed on Legendary difficulty, the scene shows the Forward Unto Dawn piece drifting to an unknown planet, which will be called Requiem in the sequel, the main setting of Halo 4's campaign.