Forerunner

Forerunner is the third campaign level of Halo 4.^[1] Completing the level earns the player the Forerunner achievement. The level-exclusive achievement This is my Rifle, this is my Gun is awarded for carrying a UNSC weapon all the way through the level on Heroic or harder.^[2]

Summary

The level is mainly set in a rocky region on the surface of the shield world Requiem, as well as a series of Forerunner structures, including two relay pylons and a satellite station inside the shell enveloping the shield world. The prototype UNSC warship UNSC Infinity has arrived near Requiem to investigate Cortana's distress beacon, and the Master Chief must disable two beam towers that are causing communications interference preventing Cortana from contacting the Infinity in order to warn the ship about Requiem's defenses. During the level, the player faces opposition from both the Prometheans occupying the shield world as well as Covenant remnant forces. The assault on the first pylon primarily involves combat on foot, while the second one is more vehicle-focused. After deactivating the second beam tower, the Chief uses a series of translocation portals to reach what Cortana assumes to be a relay satellite, while Covenant remnant warships converge on the same location; instead of a communications relay, however, the satellite turns out to house a Cryptum.^[3] The finale of the level introduces the primary antagonist of the game,^[4] the Promethean leader known as the Didact.^[5]

Trivia

During the final segment of the mission, the player can occasionally cause a glitch in the game by ramming a rock with a boosting Ghost right as the rock juts into the air. This will launch the Ghost and the player up into the air and out of the map, where they will continue to fall below the map for several seconds before the game reverts to last checkpoint.

In co-op mode, players who die during the Ghost escape sequence will respawn already riding a new Ghost, to prevent death from making it impossible to finish the level.