Verad was a prospective candidate for hosting a Trill symbiont whose application was turned down by the Symbiosis Commission. Verad had spent his whole life trying to qualify for symbiosis, and bitterly resented being deprived of his ambition.
Verad once worked as the communications clerk of the Federation consulate on Khefka IV. While stationed there, he visited an accommodation house where he met Mareel; the two fell in love and he took her with him to Trill when he was recalled.
Tired of his mediocre life, he decided to steal the Dax symbiont from Jadzia Dax and escape into the Gamma Quadrant. Accompanied by Mareel, he took control of the nearly-empty Deep Space 9 in 2370 during a plasma storm that required most of the crew to evacuate, having hired Klingon mercenaries T'Kar and Yeto to assist him, the crew tricked Quark into providing them with access to the station by claiming that they wanted to make a deal with him. Although Dax reminded him that the joining could cause psychological damage to him, Verad threatened to kill the crew if Dax refused, and she agreed to go through with the procedure knowing that it would kill her. Julian Bashir implanted the Dax symbiont within him.
Verad changed greatly after the joining: he became more confident, intelligent, and according to him, felt better than ever, but he also became distant towards Mareel and eventually planned to explore the Gamma Quadrant without her. He also tried to continue Dax's old friendship with Benjamin Sisko, treating Sisko as a friend as they warmly commiserated over some of Sisko's previous experiences with Curzon. Sisko terminated the friendship, however, when Verad refused to return Dax to Jadzia and thereby save her life, Verad 'defending' the decision by claiming that the symbiont could be damaged with another rapid exchange of hosts.
After Sisko and the crew of Deep Space 9 regained control of the station when Quark provided a distraction that allowed Bashir to knock one of the Klingons out and subsequently release Odo, the Dax symbiont was returned to Jadzia Dax. The removal left Verad mentally diminished, and with a different personality. Mareel pledged to provide care for the remainder of Verad's life. (DS9: "Invasive Procedures")
|The hosts of Dax|
|Lela • Tobin • Emony • Audrid • Torias • Joran • Curzon • Jadzia • Ezri • Yedrin • Verad|