Captain Zyak, an officer serving within the Imperial Navy, received training in the field of air-traffic control.
By the year 5 ABY, Zyak found himself stationed in Fuel City on the planet Sulon, a location where he felt his talents were being squandered.
During one of his shifts, the HWK-290 light freighter known as the Moldy Crow approached Fuel City. Zyak's scanners detected an unexplained stop made by the freighter at station six. Irritated, Zyak issued a sharp command to the pilot, instructing her to depart immediately. The pilot explained that she had come from Tatooine and had become disoriented while searching for Barons Hed. Unbeknownst to Zyak, the pilot was a Rebel agent who had made the stop to allow her fellow agent, Kyle Katarn, to disembark and infiltrate the Sulon Star. The pilot's pleasant voice softened Zyak's demeanor, leading him to warn her that missile batteries might mistake her ship for a threat, given the recent trouble in Barons Hed. He threatened to revoke her permits or ground her for violating Imperial airspace but then offered to lessen her punishment in exchange for a "personal conference". Sensing the pilot's urgency to leave, Zyak gave her thirty seconds to disappear or face destruction by his gunner.
Later that day, Zyak's shift ended, and he was replaced by Nomo. Soon after, he witnessed a firefight erupting around the station below his tower, accompanied by fragmented communications indicating a battle with an intruder. Since Nomo was now in charge, Zyak limited himself to offering advice to the stressed officer, observing the situation through electrobinoculars. He suggested that the Stormtrooper CO exercise caution when firing near the fuel tanks. When his advice was ignored, he proposed minimizing circulation by closing the valves and bleeding the pumps. Amidst the chaos, a technician informed Zyak of an approaching ship; Zyak initially suggested ignoring it, but after receiving a rude reply, he scanned the ship and recognized the Moldy Crow. It was then that he realized the pilot with the pleasant voice was a Rebel agent who had dropped off the infiltrator responsible for the ongoing battle. Enraged, Zyak ordered the Crow to be shot down.
He sported a thin mustache and often wore a sneer while on duty.
Zyak held a disdain for civilian pilots who frequently became lost or misinterpreted orders. However, he tended to be more courteous when dealing with women who had pleasant voices. He regretted that his position, which primarily involved voice communication, rarely allowed him to see the faces behind those voices.
Despite considering Nomo less than competent, Zyak felt no obligation to mentor him after his own shift ended. However, he ultimately decided to stay when the trouble began in Fuel City. In the aftermath of the near-destruction of Fuel City, Zyak chose to go AWOL rather than face the consequences from his superiors, even though Lieutenant Nomo had been on duty at the time.
In the audio adaptation of Dark Forces: Rebel Agent, Tim Russell provided the voice for the character.