One of the Eymorg, the women who live in comfort beneath the frozen surface of Sigma Draconis VI, who is captured and questioned by Kirk in 2268.
Luma appears in the third-season episode Spock's Brain. The landing party searching for Spock's stolen brain find that the planet's males, the Morg, live as primitives on the ice, while the females inhabit an underground complex whose builders they have forgotten.
Luma is the first Eymorg they meet. She arrives by the lift from the underground city, and is stunned and questioned. Her answers are those of a child. She does not know what a brain is and cannot tell them who is in charge.
She is present later when the leader, Kara, uses a pain device on the prisoners. Luma was played by Sheila Leighton.