T'Gai was a female Vulcan lower decker who served aboard the Vulcan cruiser VCF Sh'vhal.
When nearing the end of her second duty shift in late 2381, she asked three of her fellow crewmates if any of them were interested in a game of chess. When T'Lyn observed detected an anomalous concentration of metreon particles in System 7743.8, T'Gai noted that the star system was beyond scanning range of the ship's long range sensors. When T'Lyn noted that something about the readings felt off, T'Gai repeated T'Lyn's words, and reminded her that she had previously been spoken to about saying such things. (LD: "wej Duj")
T'Gai was voiced by Jessica Lowe.
Her name was not spoken on-screen, but was revealed in the episode's closed captioning, as well as the episode's script.