ADF-X011 'Natalia' was a UNSC AI created just before the attack at Cerus III, and then went into service under Lucius Clark. She served as his lab's primary AI and caretaker. Knowing her own limited life-span, Natalia is always interested in ways of extending her operational life-span. However, Natalia did eventually go rampant, but, not wanting to terminate his only companion for the past 7 years, Lucius instead isolated her in a remote sector of the lab, so that she could still exist. However, when the Flood attacked Lucius's lab and threatened Lucius and a little girl they rescued, Lyla Tesla, Natalia broke out of containment and came to their aid. She is theorized to have reached meta-stability.