Alpha Platoon

Alpha Platoon was a part of the UNSC Marine contingent aboard the in 2531. It consisted of several infantry squads and an Elephant.

During the Battle of the Flood-controlled Shield World, Alpha Platoon encountered unknown aliens while patrolling the base established by the, managing to destroy the coordinating forms. When the Spirit of Fire was attacked by Forerunner Sentinels, Serina attempted to evacuate the platoon directly, but the dropships were forced to turn back by hostile aerial forms. Along with Bravo Platoon and Charlie Platoon, Alpha Platoon fought its way on the ground through the aliens to get back to base, where they were finally evacuated. However, one Grizzly tank volunteered to remain and help evacuate the other two platoons. The base was abandoned to the aliens, now empty of personnel.