Erbus was able to help Lt. Jason Thompson recover from his wounds, impressing his captain, James T. Kirk. After Thompson was beamed back to the USS Enterprise, Erbus escorted Capt. Kirk, Commander Spock, and Dr. McCoy to facilitator Weis's office. Unfortunately, they were beamed and kidnapped by the Virtili. At first, Erbus told Capt. Kirk that they had dealing with them but they were just criminals. After escaping from their cell, Erbus then told the truth that his people were running in their shipments to the Virtili.(TOS - Burden of Knowledge comic: "Uncertain Prescriptions")