Cardassian security chief on Terok Nor before Odo, who appears in a telepathic recreation of the station's past during the occupation.
Thrax is a Cardassian who served as chief of security on Terok Nor, the Cardassian station later renamed Deep Space Nine, before Odo held the post. A rigid enforcer of Cardassian order, he appears in a telepathic recreation of the station's past drawn from Odo's memories.
In Things Past, Benjamin Sisko, Jadzia Dax, Elim Garak and Odo find themselves living as Bajorans accused of trying to assassinate Gul Dukat. Thrax refuses Odo's pleas for a proper investigation, but the illusion finally exposes the truth Odo had hidden: it was Odo, not Thrax, who had the innocent Bajorans executed. He was played by Kurtwood Smith.