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.
: Jace continues to suffer from haunting hallucinations and vulnerability following his resurrection, though he hides the severity of his condition from Clary. [S3E2] The Powers That Be
: As Magnus Bane adjusts to no longer being High Warlock, he struggles with the corruption of his magic. He and Alec Lightwood attend a warlock council gala where the infection spreads, forcing Magnus to confront the source of the demonic interference. The episode centers on a supernatural crisis affecting