Lieutenant Grant was a male Human Starfleet officer who lived during the mid-23rd century. In 2267, he was assigned as an operations division security officer aboard the USS Enterprise under Captain James T. Kirk.
That year, Grant was part of the landing party that beamed down to the planet Capella IV to secure topaline mining rights for the Federation. Unfortunately, the Capellan tribesman Keel killed Grant with a kleegat almost immediately upon arrival, after the security officer attempted to reach for his phaser at the sight of the Klingon, Kras.
Kirk was deeply troubled by the loss of Grant, who he excused for the incident as being "young and inexperienced." He was later at a loss of understanding as why Grant had to die, noting that they neither lied to nor violated any of the Capellan's customs. McCoy explained to Kirk that it was "because he was drawing a weapon on their guest," Kras, to which Kirk replayed the scene, "Grant looked up, saw a Klingon, made a purely instinctive defensive move."
Kirk later apologized to McCoy for snapping at him, to which McCoy conceded that he knew what it means to Kirk to lose a crewman. This bothered Kirk more, knowing that "that's only one down, Doctor. There's over 400 more up there in orbit."
Later, when Kirk and company were introduced to High Teer Akaar, he stated to the leader, "first, I must protest the killing of my crewman." Akaar, however, was confused by this statement, inquiring, "if it was your man, wasn't it his privilege to die for you?" (TOS: "Friday's Child")