This article or section contains information about StarCraft: Ghost, which has been declared non-canon. Elements may be taken as 'flavor lore' however.
After a terrazine explosion on Mar Sara, which attracted a massive swarm of zerg to the planet, Den and his squad were assigned to aid Captain Buck and his squad as they took the refinery. Den sat quietly as Lister antagonized the ghost agent assigned to them, Nova, not knowing she was female when he tried to pick on their masculinity.
On the way to the drop zone, two of their dropships, Doomhammer and Lightbringer were shot down, forcing their squad to land twenty clicks away from their destination. They were forced to fight through waves of zerg to reach their target.