What Exactly Does The Halo Ring Do?

Spoilers are ahead for Halo season 2.

Although the multimedia franchise derives its name from its iconic ring, viewers might be wondering what, exactly, the ring world does ahead of Halo season 2’s finale. Introduced in the series’ first-ever game, Halo: Combat Evolved, the Halo ring isn’t just a key component of the narrative, but a symbol that’s as iconic as Master Chief (Pablo Schreiber) and Cortana (Jen Taylor; Christina Bennington). Well before Halo season 1’s ending, John-117 (Schreiber) learns that the Forerunner keystones lead to an alien superweapon of unparalleled destructive power — a.k.a. “the Halo.“

The Paramount+ series definitely clues viewers into the so-called Sacred Ring’s true nature much earlier than Halo: Combat Evolved did. Even so, it’s clear that neither the humans nor the Covenant understand Halo’s true purpose — or the magnitude of its devastating power. In Halo season 2, episode 7, Shabana Azmi’s dangerous ONI officer, Admiral Margaret Parangosky, commands waves of Spartan-IIIs to ensure the superweapon doesn’t fall into the Covenant’s possession. Meanwhile, both Covenant “blessed ones” — the Covenant-raised human Makee (Charlie Murphy) and John — are headed toward the ring.

The Halo Ring Is Actually One Of Seven Ring Worlds

The Covenant Worship The Forerunner Halo Array

At the beginning of Halo: Combat Evolved, the UNSC’s Pillar of Autumn exits slipspace and gets into a scuffle with Covenant forces, prompting Captain Jacob Keyes to entrust the ship’s A.I., Cortana, to Master Chief, and crash-land the Autumn on a ring world. With the story’s characters split up from each other time and again, they each learn fragments of the Halo’s true nature. Interestingly, the ring-shaped superweapon that’s seen in Combat Evolved is one of seven that comprise the Forerunners’ Halo Array. Known as Installation-04 or Alpha Halo, the Covenant reverentially dub it the First Sacred Ring.

The Halo Array is the name for the entire network of colossal ring-shaped superweapons. Although the Forerunners initially constructed 12 installations, or Halo rings, their numbers dwindled, leaving just seven ring-worlds left. Not only are the installations that comprise the Array devastating weapons, but they are also dedicated research facilities. A Halo’s Library is not just a repository of knowledge, for example, but a collection of genetic material from the galaxy’s sentient life forms. However, even the scientific-minded purpose of the Halo installations stems from the Forerunners’ war with the Flood.

The Forerunners Developed The Halo Array To Starve The Flood

A Superweapon Meant To Sterilize The Galaxy

Centuries before the Human-Covenant War, a different conflict threatened all sentient life in the galaxy — the Forerunner-Flood War. While the Forerunners were a technologically advanced, adept civilization, their empire faced extinction when the “deeply alien threat” called the Flood arrived. A corrupted form of the Precursors, the galaxy’s original custodians, the Flood is a species of parasitic organisms that reproduce and grow by infecting other organisms and transforming them. By infecting sentient intelligent lifeforms, the Flood gains its hosts’ knowledge and memories, which is a huge boon to a hive-mind like Halo‘s Flood.

If there’s an adequate supply of lifeforms, the Flood will grow. After realizing the parasitic species’ truly devastating power, the Forerunners created several defensive and war-ending measures, including the Halo Array. However, the superweapon isn’t designed to destroy the Flood directly. Instead, the Array starves the Flood by eradicating its food source. A galaxy-sterilizing weapon, the Halo Array is capable of wiping out all sentient life in its range. To end the war, the core canon Halo lore sees the Forerunners activating the Halo Array. Afterward, the surviving Forerunners repopulated the galaxy’s sentient species using specimens they’d gathered.

How The Halo Ring Differs In The TV Show

The Halo Array & Its Installations Appear Throughout The Core Canon

While the Paramount+ series takes place in the separate Silver Timeline, the narrative is still heavily inspired by Halo‘s core canon. Although the TV show introduces new characters and twists on the franchise’s pre-existing lore, the broader strokes remain familiar. Halo season 2’s Fall of Reach episode is a good example of that: it differs from the game and book interpretations, but the fallout leads to similar beats. Now, with Halo season 3 primed to feature the Flood as its main threat, the true intentions behind the Halo Array will no doubt come to light.

In the core canon, certain members of the Covenant become disillusioned with the Great Journey, the Forerunners, and the Sacred Rings once they realize activating the Array ensures the eradication of their species. The revelation certainly shocks Master Chief, who destroys Combat Evolved‘s Installation-04. The Halo season 2 finale sees both the humans and the Covenant racing to seize control of the Halo, believing it has war-winning potential — or, in Makee’s eyes, the potential for unifying good. Clearly, the reveal about the superweapon’s intended targets will reshape both sides as the fight continues in Halo season 3.