Ensign Garrovick was a 23rd century Starfleet security officer aboard the USS Enterprise under Captain James T. Kirk. Garrovick's father was the former commander of the USS Farragut. He and ensign Rizzo were good friends and Starfleet Academy classmates.
In 2268, a newly transferred Garrovick reported to the bridge of the Enterprise and learned of Rizzo's death from Nyota Uhura, who was presenting a reporton his condition to Kirk at the time. Kirk offered Garrovick the chance to avenge Rizzo's death, once he learned of their friendship. Kirk and Garrovick encountered the same dikironium cloud creature on Argus X that killed his father, and two hundred crewmembers from the Farragut, eleven years earlier.
Garrovick sighted the creature but was, however, temporarily paralyzed and unable to shoot it. Kirk blamed Garrovick for his hesitation, a blunder which caused the death of two security officers. He was subsequently relieved of duty and confined to quarters until further notice, a punishment Leonard McCoy viewed as harsh in light of the circumstances.
Guilt-ridden, Garrovick lay around in his quarters, only to be visited by Nurse Chapel, who brought him some dinner as per Doctor McCoy's orders. He asked her for an update and she gave him one, adding that he was lucky to not have to deal with the situation. Though Garrovick refused the food twice, Chapel showed him a memory tape and told him that it was McCoy's officially logged prescription for the man to eat, adding that if he didn't comply, McCoy could and likely would have him dragged to sickbay and fed intravenously. (In reality, the tape contained A Survey on Cygnian Respiratory Diseases).
It was later discovered that Garrovick's hesitation was unintentional and that phaser fire would not have harmed the creature. When Spock came to tell him that, the creature tried to enter his quarters through the air vent. The first officer ordered him out of the room while he attempted to stop it.
Kirk allowed Garrovick to redeem himself upon the ensign's request. Together, they set a trap for the creature, which consisted of a container of red blood and a matter/antimatter bomb. The two beamed back to the Enterprise, moments before the bomb went off, which at the same time, destroyed the cloud creature. (TOS: "Obsession")
Background information Edit
While the character's first name was not established through dialogue, the sign to Garrovick's quarters read: "David Garrovick."
The character has appeared in multiple novels and comics, and has variously been given the first name David (Star Trek 9 by James Blish), Stephen (In the Name of Honor by Dayton Ward) and Tom (Debt of Honor comic by Chris Claremont).