An Enterprise officer whose family's losses in the Earth-Romulan War leave him suspicious of Spock in Balance of Terror.
Lieutenant Andrew Stiles takes over as navigator during the Romulan crisis in Balance of Terror. Several members of his family fought in the Earth-Romulan War, and when the Romulans are revealed to resemble Vulcans, Stiles openly suggests that Spock may be a spy, earning a rebuke from Kirk.
During the battle, Stiles is overcome by coolant gas in the phaser room, and it is Spock who rescues him, as well as firing the phaser himself. Stiles is forced to confront his prejudice after the Vulcan saves his life. He was played by Paul Comi.