|Out of universe information|
Firnan was a male human who bounded with the Tok'ra Cordesh. While on an undercover mission for the Tok'ra, his cover was blown by Kryse who took Rosha as a host and Cordesh was removed out of him and replaced by a Goa'uld named Anker. He then left back to the Tok'ra to spy on them against his will.
When the Tok'ra finally discovered he was the traitor, Anker jumped to a new host: Liandra and Firnan, unable to cope with his shame later committed suicide by walking into one of the collapsing tunnels which crushed him, resulting in his death. (RPG: "Friends and Foes: Stargate Season Two") (SG1: "The Tok'ra, Part 1", "The Tok'ra, Part 2")