Arcane Season 2: What Is the Grey (& Why Does It Matter)?

Warning: The following article contains spoilers for Arcane Season 2 Act 1.

Arcane‘s second season adds a key concept to the Netflix animated series’ lore: the Grey. So, what exactly is the Grey, and why does it matter so much in Arcane Season 2?

What Is the Grey in Arcane Season 2?

The Grey first enters the spotlight in Arcane Season 2 Act 1, Episode 2, “Watch It All Burn.” Here, it appears as an unnamed gas Caitlyn, Vi, and their fellow Enforcers unleash during a raid on Zaun. Act 1, Episode 3, “Finally Got the Name Right,” subsequently supplies the gas’s name, as well as its origin story. Dialogue in Episode 3 labels it “the Grey” and reveals it’s “factory smog trapped underground.”

So, essentially, it’s all of Piltover’s industrial pollution emissions combined into a single (and extremely unhealthy) vapor. The Grey’s short-term effects include damage to the eyes and lungs. Arcane Season 2 also implies the gas may have far more extreme long-term side-effects, such as genetic mutations or even death. Bottom line? No one should be breathing it.

But why is the Grey only becoming a problem now? Because until Arcane Season 2, the Grey was under control. As Caitlyn (and viewers) learn in Act 1, Episode 3, Caitlyn’s mother, Cassandra, ordered the Kiramman Clan’s architects to build an elaborate ventilation system throughout Zaun to contain the Grey and purify the Undercity’s air. But in Season 2 Act 1 that system is compromised at least twice. Not only does Caitlyn temporarily unleash the Grey on Zaun’s residents in Episode 2, but Jinx’s bombs blast open a vent and expose Piltover’s population to the gas in Episode 3.

Related: Arcane: How Old Is Jinx in Season 2?

Why Is the Grey So Important in Arcane Season 2?

Obviously, the Grey gunking up Piltover will be a major plot point in Arcane Season 2’s two remaining acts. Aside from the immediate health hazard it presents, Zaun venting a toxic substance into Piltover – even one Piltover itself created – will inevitably escalate tensions between the two communities further. And on a more character-driven level, Caitlyn’s use of the Grey in Act 1 reflects her vengeance-focused arc, which Acts 2 and 3 are guaranteed to explore further.

Related: Arcane: Who Is Isha (& How Is She Connected to Jinx) in Season 2?

There’s also the possibility that the Grey will wind up being even more insidious than what we’ve seen so far. As several fans have already noted, a monstrous face appears within the Grey throughout Arcane Season 2 Act 1, hinting that it’s actually a malevolent (and possibly sentient) being. Admittedly, this could simply be artistic license on the Arcane creative team’s part. But it could also be a clue that the Grey will pose an even bigger threat in Arcane‘s final six episodes!

Arcane Season 2 Act 1 is currently streaming on Netflix. Acts 2 and 3 drop on Nov. 16, 2024 and Nov. 23, 2024, respectively.