After spartans Douglas-042 and Alice-130 clear The Banished base that is preventing them from travelling to the new halo ring (Installation 09) and prevent any more banished reinforcements from leaving, they are able to join Jerome-092, along with a sizeable UNSC force, on the ring and assist them in their mission of getting Professor Anders to the control room before The Banished.
During this mission, Red Team clears the surrounding area of all Banished forces under the command of Atriox, and gains control of and holds three control towers outside of the control room in order for Anders to be given access to it. While taking control of and holding the towers, the ring sends out forerunner defences in an attempt to prevent them from gaining access to the control room. Amongst these defences are retriever sentinels, large flying forerunner defence drones with devastating ranged attacking abilities.
After the UNSC maintains control of the towers for long enough and fighting off the banished, Anders is eventually able to gain control of the retriever sentinel and uses it to destroy the final shield that is protecting the control room, giving her access to it so that she can complete her goal of disarming the ring's weapon systems.
|Sentinel size matters||Completed The Halo||10G|