In the episode "Amnesia", X.A.N.A. created a Nanobot and injected it into Mrs. Hertz's collection of nanobots. Later during science class, as a prank, Odd unknowingly put the nanobot on Ulrich's nose, where it crawled into his nasal passages and into his brain, where it started wiping out his memory centers, giving him amnesia and causing him to forget everything. When Sissi came to visit Ulrich in the Infirmary after he fainted, the nanobot spread to her body, then to Herb's, Nicholas's, and eventually to the rest of the school's, giving them all memory loss. Once the Tower X.A.N.A. had activated was deactivated, Jeremie activated a time reversion. This time, Ulrich burnt the nanobot substance to end the threat.