Theena elMadej was a female Payav of the nation-state of Larenda on planet Mestiko. Theena was a young girl when "The Pulse" hit Mestiko in 2265, and was separated from her parents at the height of the crisis. In the chaos, she was found by Raya elMora, who guided Theena to safety. (TOS - Mere Anarchy eBook: Things Fall Apart)
Theena's parents were presumed dead in the wake of the Pulse, and Theena was placed in an orphanage. Raya remained in close contact with her, however. (TOS - Mere Anarchy eBook: The Centre Cannot Hold)
By 2283, Theena had earned the title Doctor and established herself as one of Mestiko's most accomplished young scientists. Theena proposed the establishment of the Discovery Center on Varnex, which would be a symbol of Mestiko's self-sufficiency, and their ability to take the lead role in the interstellar community. Because of her youth, her mentor, Dr. Hovda elZana was made the first director of the center, until Theena was deemed old enough and took the position.
By 2291, Theena developed a prototype subspace-disruption weapon, and formed an alliance with Vykul Marto, founder of the Torye. Feeling her old friend, Jo'Zamestaad Raya elMora had formed too tight a bond with the Federation, Theena aided the Torye in stealing the weapon from the Discovery Center. However, she turned against Vykul when he attempted his own grasp at power, and helped a joint team of Starfleet and Klingon personnel defeat the Torye.
After being taken into captivity, Theena intended to plead guilty to all criminal charges against her, without aide of counsel. (TOS - Mere Anarchy eBook: The Blood-Dimmed Tide)