Heffilmurm was captain of the Lingolf Garrison in 398 GUE. Heffilmurm marched with Zilbo Throckrod and General Darborn Griffspotter to the Jerrimore Plains where they came upon the remnants of the battle between Mareilon and Galepath, which had both been destroyed by the Nezgeth warriors.

The captain, well-versed in the geography of Quendor's outlying areas, was the one to inform Zilbo of the location of Belegur's lair as it conformed to the Scrolls of Kar'nai. Allied with the Nezgeth, he marched with Zilbo and the Nezgeth to the lair of Belegur (which is today known as the Griffspotter Caverns). He and his men remained outside, while Zilbo and the Nezgeth entered and defeated Belegur. Skeptical about the death of Belegur, Zilbo requested for Heffilmurm and the core of the Lingolf Garrison to stay behind at the sight of the battle.