Battle of MombasaEdit
- Main article: Battle of Mombasa
The company's facility in New Mombasa became a command post for "A" Company of the UNSC Marine Corps when the Covenant attacked in the Battle of Earth. The commanding Marine Lieutenant of the company was killed before the company could enter the building and the Covenant pinned down the company with several Ghosts, a pair of Wraith tanks and a pair of Jackal Snipers. "A" Company fortified Mtangulizi Kampuni, placing Marines with heavy weapons in the stairwells and even mounting several M247 GP Machine Gun turrets. The third floor, which was adjacent to a canal, sported a heavy armory with large numbers of M19 Rocket Launchers, M90 Assault Shotguns, BR55 Service Rifles, and numerous ammunition cartridges.
When the UNSC launched an offensive to retake the city center, John-117 spearheaded an assault to liberate "A" Company from Mtangulizi Kampuni, and with the aid of a nearby Marine-crewed M12 Warthog LRV, attacked the Covenant force situated in front of Mtangulizi Kampuni. The Covenant attempted to reinforce their group with two Ghost vehicles air-dropped by Phantom, but were ultimately unsuccessful. After all nearby Covenant forces had been destroyed, the Marines unlocked the front doors to Mtangulizi Kampuni, allowing SPARTAN-117 entrance. Corporal Perez introduced SPARTAN-117 to the acting company commander, Sergeant Banks, who was on the second floor. Later, two Pelican Dropships air-dropped a fireteam of Marines and an M808B Scorpion Tank nearby Mtangulizi Kampuni, but a Covenant Scarab walker that was tunneling towards the city center engaged them, completely destroying the reinforcements. Banks promptly ordered his men to assault the Scarab as it passed by the third floor, and SPARTAN-117 went to assist them.
The Scarab eventually got stuck in the canal, and was unable to move any further because of obstructions in the canal. A Pelican Dropship attempted to bombard the massive walker with ANVIL-II Air-to-Surface Missiles, but the missiles didn't even scathe the armor plating, forcing the UNSC forces to board the Scarab if they were to bring it down. While a small team of Marines fired down on the Scarab, SPARTAN-117 jumped aboard, killing its crew and its Ultra Elite commander, and then destroyed the walker by unknown means, probably sabotaging the interior mechanisms.
A Pelican Dropship commanded by Sergeant Major Avery J. Johnson then landed near Mtangulizi Kampuni, retrieving SPARTAN-117 and also an unknown number of Marines, including Perez, bring them back to the nearby UNSC frigate UNSC In Amber Clad. The company's building was destroyed when the city was later glassed by the Covenant.