The Caretaker
At the suggestion of the Caretaker, Arid descends into the laboratory areas of the facility to find the Administrator's central access panel, because it can be used to override his test protocols which require her to lie. She encounters infestations of dangerous local flora and fauna, which presumably contributed to the facility's abandonment, including: fungi which produce a highly potent acid, piranha-like fish capable of biting through steel, and massive slug creatures. Once she reaches the mainframe's primary access room, the Caretaker appears and sabotages her power systems declaring her faulty and needing to be de-purposed immediately. Arid solicits the Administrator's help to obtain repairs, but the Caretaker re-emerges while Arid is incapacitated in the repair chamber. The Caretaker uses the opportunity to declare the Administrator faulty for assisting her, and implements a complete format on the mainframe, destroying the Administrator's sentience and returning him to his original programming.