Cortana informs the Arbiter and Masterchief that the flood are trying to establish themselves on the newly constructed Halo. Arbiter, Masterchief and Johnson fight their way to the control room where they are betrayed by Guilty Spark who wants to preserve the Ark even in the face of iminent contamination. In the fire fight that follows, Johnson is killed by Guilty Spark who is then destroyed by Masterchief and Arbiter. The two then activate the unfinished Halo and use Johnson's Warthog to reach Forward Unto Dawn; a UNSC ship which they then use to escape the Ark which explodes as the Halo activates. Arbiter is seen being rescued from the crashed ship which landed in one of Earth's oceans, but Masterchief and Cortana are no where to be found. A memorial is heald for Masterchief, Johnson and the other soldiers lost in the war for the Ark. After watching the credits, the player learns that Masterchief and Cortana are still alive and Masterchief enters a cryo-chamber and is frozen to await rescue. If you beat the game on legendary dificulty, you see the half of Forward Unto Dawn that Masterchief and Cortana are in; drifting towards an unknown planet.