The episode centers on a supernatural crisis affecting the warlocks of New York. Their magic is becoming "corrupted," manifesting as a dark, oily residue that causes them pain and renders their spells unpredictable or dangerous.

Report: Shadowhunters Season 3, Episode 2 — "The Powers That Be"

: This serves as the first major physical sign of Lilith's influence on the earthly plane, highlighting that even the most powerful supernatural beings are at risk.

: Isabelle Lightwood and Luke Garroway team up to investigate a series of mundane possessions. Their trail leads them to a connection with a powerful, emerging demonic force.

: The episode further establishes Lilith, the "Mother of All Demons," as the primary antagonist. She is revealed to be the source of the warlock corruption, using it as part of her larger plan to resurrect Jonathan Morgenstern. 🗝️ Key Themes & Developments

: Magnus navigating life without his High Warlock title provides a rare look at his vulnerability and identity beyond his position of power.