Battle of Alpha Base

The Battle of Alpha Base was a military engagement between the UNSC Marine Corps and the Covenant during the Battle of Installation 04.

Prelude
Prior to the battle Zuka 'Zamamee formulated a plan to eliminate John-117. His Grunt offsider, Yayap, was left to be found by the UNSC forces, and transported to Alpha Base. Once he spotted the Master Chief, he activated a signaling device to call in Zuka's attack force. However, by the time the battle had started, the Master Chief was well on his way to the Installation 04 Control Room.

Attack on Alpha Base
The Battle for Alpha Base began with a distress relay call from the Pelican dropship Charlie 217. This Pelican had been listed as MIA, and so was allowed to land on one of the pads at Alpha Base, although a Marine reaction force was put on standby. The Pelican was piloted by Lieutenant Rick Hale, a Covenant prisoner. As soon as the Pelican was given permission to land, the Lieutenant was strangled to death by Zuka 'Zamamee using an energy garrote. Wellsley, the Alpha Base AI, detected six additional heat signatures behind the Pelican which he recognized as Spirit dropships inbound at 350 kph. Though he was unable to prevent Charlie 217 from landing, he was able to warn his superiors to mount a response.

Thirty heavily armed Stealth Elites disembarked from the dropship and attacked every Marine in sight. Despite being caught mostly unaware, the UNSC forces rallied and fought back, flooding the landing pad with fuel and setting it aflame with a grenade, killing a number of the Elites and destroying the Covenant-captured Pelican.

Wellsley utilized a 50mm Autocannon and shot down one of the Spirits before they could get out of range. The 5 remaining Covenant ships touched down on the mesa and unloaded the main attack force, as well as Field Master Noga 'Putumee. Meanwhile, Zuka 'Zamamee and five of the remaining Stealth Elites descended into the underground level of the base, slaughtering all the humans that they came across. Finally, they entered the Control Room and massacred technicians Cho, Pauley, and Murphy. However, they were seen by Wellsley, who promptly warned Silva. Soon, six teams of 3 Marines were sent out to halt the Stealth Elites; to counter the active camouflage, the Marines had special items which allowed them to read the thermal heat given off by the active camo. The Elites questioned everyone they came across in an attempt to learn the Master Chief's whereabouts. Eventually they came across Yayap and three other Grunts in a prison cell. The Grunt convinced Zuka that the Spartan was guarding a group of captured Banshees on the other side of the base, and led the group toward there. A three-man Marine fireteam surprised them, killing the five Stealth Elites and the three Grunts before being taken out by a plasma grenade from Yayap. Upon reaching the Banshees, Yayap pointed a plasma pistol at 'Zamamee's head to get Zuka to fly them both to safety.

Meanwhile, on the plateau, McKay was in command in halting the Covenant forces on the plateau. The primary Covenant attack force had been thoroughly destroyed. First, the snipers attempted to kill the majority of the enemy ground forces. 'Putumee, unable to land on the pads as originally planned, alternatively landed on the area up-spin of the Forerunner complex. Despite having the remaining Spirit dropships strafing the Marine defenders, they were caught unaware by the pair of entrenched Scorpion tanks and prepared defenses on the plateau. Not only did the Scorpions obliterate the majority of the Covenant forces, but also deprived the Covenant forces of their leadership when 'Putumee was killed. However, the assault moved onward, albeit slowly, as the lower-ranked Elites assumed command and attempted to rally the troops without much success. Soon, the strafing Spirits picked up the few surviving Covenant troops and retreated.