A faithful lieutenant of Brosin Underground leader Randle Clanse, Marn led the largest of the four teams in the Brosin Underground (which must have included more than thirty men). Marn's team operated in the Reyno and Nihun valleys, and they attempted to harass the Corporate Sector Authority's industrial activities on Brosi, particularly the Zinsian processing plants.
Due to the Underground's efficiency, the Rebel Alliance was afraid of the CSA increasing its security, which could have led to the discovery of Rebel underground agents, or of a Rebel ten-men cell led by Abil Vilorin. As of 2 ABY, Vilorin had been trying to make contact with Marn, but found it very difficult. Even then Vilorin doubted he could really convince Marn to change the Underground's plans.
- Alliance Intelligence Reports