Lieutenant Commander Lang was a Starfleet officer assigned to the USS Enterprise in the 2260s, under the command of Captain James T. Kirk. In 2267, Lang was one of three tactical officers who were asked to accompany Captain Kirk's landing party to the Earth observation post on Cestus III. As soon as they arrived they discovered that the outpost had been destroyed by the Gorn. Unfortunately, Lang was killed while trying to deploy the landing party's flank and scouting possible locations of the attackers. (TOS episode & novelization: Arena)