The UNSC Spirit of Fire (CFV-88) was a heavily modified colony ship in service with the UNSC Navy commanded by Captain James Cutter and serviced by the AI Serina. The ship was assigned by Admiral Preston Cole to investigate Covenant presence on the colony of Harvest in 2531. It was also present at the First Battle of Arcadia, in which it assisted local forces in evacuating civilians and counterattacking against the Covenant. After the vessel's resident researcher, Prof. Ellen Anders, was kidnapped by an Arbiter at the behest of the Prophet of Regret, the Spirit followed a Covenant capital ship from Arcadia to a Flood-infested shield world. There, they were caught in a lengthy battle to stop their alien enemies from aquiring a fleet of Forerunner combat ships that could easily overwhelm the UNSC fleet. They did so by utilizing the ship's faster-than-light travel reactor to cause the dwarf star inside the shield world to go supernova and explode, vaporizing the ships. Without their FTL reactor, the Spirit could not jump into Slipspace to get home quickly. The ship was last seen moving through space on a voyage back to the Inner Colonies that would take decades. Its fate is unknown.It is though likely that it arrived on Reach since every Spartan II team was present except Gray team.