Battle of Trove

The Battle of the Flood-controlled Shield World was an engagement fought between the Marines of the Spirit of Fire, the Covenant, and the Flood on a Forerunner Shield World during the Human-Covenant War on February 23rd, 2531.

Background
When the Arbiter kidnapped Anders and took her to the Flood-controlled Shield World to activate the Forerunner ships within the Shield World. The UNSC Spirit of Fire followed in close pursuit. Upon entering the system they followed Anders' transponder signal the best that they could. Captain Cutter launched Sergeant John Forge to begin surface operations to locate Professor Anders.

Initial actions
Recon Teams Echo and India deployed on the planet's surface, along with a small force led by Forge. Using Elephant's and Marine infantry, together with air support from Shortsword-class Bombers and help from SPARTAN Red Team, Forge's force cleared an area of Jiralhanae around a beacon, awaiting the arrival of reinforcements and the Recon Teams.

First encounter
Shortly after this, however, the force recieved an ominous message from Echo Team, stating that they were under attack from "things," before dropping out of contact. India Team sent a similar message before dropping out of contact.

Forge's team and the SPARTANs moved to investigate, encountering the Flood for the first time, including dozens of Infection Forms that resulted in a large number of Marines being lost. However, they successfully recovered both team's Elephants and retreated back to the Firebase being constructed at the beacon site.

Red Team discovered that a Proto-Gravemind was coordinating the Flood forces and was also jamming Ander's transponder signal. However, before they could destroy the Gravemind, their Warthog was overturned and they had to be rescued by Forge's Marines. After contending with Flood Swarms and Thrasher Forms, the Marines were able to rescue the SPARTAN's and destroy the Gravemind.

Descent
After destroying the Proto-Gravemind, the Spirit of Fire's A.I Serina located Anders' signal, which was apparently in the middle of a giant sea. While the Spirit was hovering over the sea, the doors of a huge submerged entry into the planet opened and several Foreunner Sentinels flew out. The thrusters of Spirit of Fire was unable to maintain altitude over the sudden, gaping hole in the planet and inevitably began a controlled 'fall' into the rift, and forces on the Shield World's surface had less than twenty minutes to fight their way past hundreds of Flood forms before being airlifted back to the Spirit of Fire. Flood Swarms made air support almost useless, forcing the Marines to use large numbers of Wolverines to clear the air before tanks and infantry could clear landing zones of Flood growths. They managed to slow down the Spirit of Fire's descent by destroying Forerunner towers with Gremlin Combat Support Vehicles, giving them a little longer. After evacuating Alpha Platoon and Bravo Platoon, the team had to escort Charlie Platoon back to the firebase for extraction after their Pelican was forced to abort its run. After extracting all UNSC forces, the firebase was abandoned to the Flood and the Spirit of Fire began her descent.

Fighting their way down through a conduit, the Spirit of Fire was attacked by even more Flood forms. Flood growths began to sprout on the ship's hull, and Marines and aircraft were forced to fight on the hull of the ship to remove the Flood forms. Furthermore, Sentinels attacked the Flood, and while they initially provided some support to the UNSC, after pasing through the first decontamination ring, the Sentinels identified them as possible infection vectors and relabled them as targets. The UNSC forces managed to clear the hull of growths, removing the Flood and thus allowing the Sentinels to withdraw.

Aftermath
The Spirit of Fire's power core was damaged during the battle. This proved to be a shortcoming in the later Battle of the Apex, where Marines again had to deploy to the hull to repair the core and remove Covenant forces.