Directly after Halo 3, the famous Arbiter begins a search to recover a possible ancient Forerunner relic the Prophet of Truth told the Covenant was only myth.
The only remaining records that were recovered from the Prophet of Truth indicate the name of something called the Vim, the Temple, and a great source of power located in the Athensir System, on the planet Shiver.
The Arbiter will find redemption for all of his people's sins against humanity by uncovering this hidden secret and giving it, if possible, to them. With it, humanity will surely have the power to protect themselves from annihilation.
The first location the Arbiter discovers as he descends deeper beneath the surface of planet Shiver is dubbed Installation: Plato's Cave. Plato's Cave is also my first Competitive Forge map in the Plato's Cave series. It is titled Plato's Cave: Outer Sectors.