His ship's engines were malfunctioning, and he was using Enterprise's plasma exhaust to replenish the engines. Trip Tucker boarded his ship in an attempt to fix the engines. Later, when Trena'L again encountered the same problem, he tried to use the exhaust of a Klingon battle cruiser. When the Klingons discovered them, they were going to destroy the Xyrillian ship. Captain Jonathan Archer negotiated a trade between the Klingons and Trena'L. The Klingons agreed to let the Xyrillians go if Trena'L uploaded his ship's holo-programs to the Klingons. (ENT: "Unexpected")