Jeremy and Aelita program false source codes that will destroy any specter that tries to take them from a Lyoko Warrior, and tests it using Ulrich as a guinea pig. Ulrich is told to wait at school until he spots a specter and deliberately touch it to transfer the fake source codes to it to test if they work. A specter with hypnotic abilities appears the same day. If the specter manages to catch someone's gaze, it can send them into a trance-like state which the specter can use to approach a Lyoko Warrior and take their actual source codes without them fighting back. Ulrich manages to test the false source codes and destroys the specter, but it knocks him unconscious for a while. Jeremy decides not to try it again as it is too risky.

While the Lyoko Warriors prepare to take advantage of a sunny afternoon, XANA launches an attack, sending them a polymorphic specter disguised as...them, constantly changing its appearance! Plus, not content with fighting unexpected specters at the school, our heroes are confronted with false avatars of themselves on Lyoko. Paranoia will soon settle in. And it's chaos on Lyoko as more false avatars keep showing up one after the other.