From Halopedia, the Halo wiki
"Control" was a Forerunner structure occupied by the Covenant remnant during the Battle of Requiem. The Sentinel Aggressors from the structure were defending it against the Covenant, who were attempting to gain entry to the Terminus inside the structure. When John-117 first crash-landed on the shield world, Cortana led him to "Control" so they could access the Terminus.
Six months later during the Requiem Campaign, Jul 'Mdama's Covenant stored stolen UNSC weapons and equipment in this location. After Fireteam Crimson escaped from a Covenant detention center onboard a hijacked Phantom with TJ Murphy of Icebreaker squad, the Covenant at "Control" ordered their Phantom to land, unaware that the craft had been hijacked. Fireteam Crimson left the Phantom to engage the Covenant forces in the area and they found out that the Covenant had placed terminals in the structure. Roland, with help from Fireteam Crimson, planted worms into the terminals and used them to hack into the Covenant network. However, after planting the third worm, the entire system shut down, and Covenant reinforcements entered the area to eliminate Crimson. After defending themselves, Crimson destroyed two Covenant radar nodes to reactivate the system, allowing the Covenant intel to continue its loading into the UNSC Infinity's systems. Crimson cleared a landing zone, and Murphy returned with his Phantom to extract them. The information gathered here would later lead Crimson to a Covenant central intel center.
Later, Dr. Henry Glassman directed Fireteam Crimson back to the location to test out Spartan Anthony Madsen's looted Requiem map. Crimson was led around the area, activating Forerunner technology such as an Z-510 Focus turret anti-infantry defense network, Promethean weapon caches, and four Forerunner anti-aircaft cannons. Glassman's successful ability to lead Crimson around the area proved his ability to read the map which Glassman predicted could help to free Infinity from Requiem. After successfully securing the location from Covenant forces, Infinity Spartan Commander Sarah Palmer pulled Crimson back to the ship, commenting that she will give the Fireteam ribbons for their "science fair project."
After the abduction of Dr. Catherine Halsey, Roland traced her bouncing signal to "Control" from "Cyclone" and Crimson was redeployed to the area which had once again been retaken by the Covenant who took out the defending Boa Squad before Crimson could help them. Fighting through the enemy forces, Crimson activated three Covenant comm terminals, ultimately allowing Roland to track the signal to "Apex." As Roland hacked the data on the last terminal, Crimson came under attack from vast Promethean forces. Finally, after Crimson reached a safe location, Robert Dalton commenced an aerial bombardment of "Control" that eliminated the remaining Prometheans, allowing Crimson to be picked up for transport to their next mission.
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