Installation 05

In the video game Halo 2, Installation 05, also known as Delta Halo is one of the Halo Installations built by the Forerunners to contain the Flood. It is also one of the rings that The Covenant is searching for to control them to complete the Great Journey.

When the High Prophet of Regret fled New Mombasa and used the slipspace rupture to self-destruct the City after Master Chief destroyed the Scarab, he set up a Base of Operations on Delta Halo I-05 to make the first attempt to activate it. Master Chief followed him there and assassinated him.

Delta Halo I-05 has submerged structures and ruins and has little-known wildlife too.

Delta Halo I-05 is the scene of many battles between the UNSC, the Covenant, and the Flood in the race for the Index and its Library is the home to the omniscient commander of the Flood, Gravemind.

When the High Prophets and the Brutes betrayed the Elites, the Brutes set up a Base of Operations in the Control Room building to activate this Halo Installation while the High Prophets' Forerunner flagship heads for Earth in search of the Ark. The uneasy UNSC-CS Alliance launches an offensive against the Brute encampment and the Arbiter kills the High Prophets' Brute Chieftain Tartarus. The Index was retrieved and Delta Halo I-05 cannot fire. However, it sends signals to other Halo Installations and they are ready for remote activation from a core installation known as The Ark.

Halo 3 will presumably pick up where this storyline leaves off. The fate of Delta Halo is unknown.