|Warning: This article may contain plot spoilers.|
Halo is the final level of Halo 3. The level starts at the site of a crashed pelican, where the player moves forward, and Flood dispersal pods fly down. Master Chief must journey up the tower with the assistance of Sgt. Avery Johnson's Spartan Laser. After eliminating the Flood, the player is prompted to enter the activation chamber. Once there, Johnson tries to activate the Halo prematurely, which would cause The Ark to explode. 343 Guilty Spark mortally wounds Johnson and attacks the Chief and the Arbiter. Master Chief is assisted by Johnson in the destruction on 343 Guilty Spark and activates the Halo. Master Chief escapes the destroying Halo by Warthog and gets to the Frigate. The Arbiter goes and pilots the Forward Unto Dawn while Master Chief lets Cortana start up the frigate. While escaping, the back half of the frigate, where the Master Chief and Cortana are, they fail to make it through the portal. Afterwards, a short cutscene depicts a small memorial dedicated to the Master Chief and Cortana.