Lieutenant Commander Lang was a Starfleet officer assigned to the USS Enterprise under Captain James T. Kirk. Lang was one of three tactical officers who beamed to the Earth observation post on Cestus III in 2267. Arriving, they discovered the colony had been destroyed by the Gorn, a previously unknown species. Captain Kirk ordered Lang to deploy on the landing party's flank, presumably to scout likely locations of the attackers. Shortly after this, Lang was killed. Of the three tactical officers, only Kelowitz survived this attack.