After reading about a dead man named Leon Corbe, who died during the construction of Kadic, Sissi decides to hold a séance to communicate with him. She manages to convince Ulrich to attend. During the séance, one of Xana's ghosts appears in the form of a four-armed monster. At first, it seem docile, but quickly gets angry and attacks. Ulrich leaves Sissi with Odd while he goes to tell Jeremie. Jeremie can't find an activated tower, which seems wrong considering the situation. As Jim patrols the hallways, he is picked up by an invisible object. Jeremie, Odd, and Ulrich arrive to spray it with a fire extinguisher, confirming that it's a ghost and implying that the super scan is broken. With the ghost on the loose, the group heads off to the factory. After they arrive, Aelita, Odd, and Yumi head to Lyoko. Odd looks for the tower while the other two head to The Carthage Region to fix the super scan. Meanwhile, Jeremie and Ulrich are left to deal with the ghost.
