He assisted Dendybar's apprentice Sydney along with Artemis Entreri in their quest to find both Regis and the crystal shard Crenshinibon. However, Catti-brie, in an attempt to help the Companions of the Hall, persuaded Jierdan that Sydney and Entreri would dispose of him once he was of no more use. Eventually, Jierdan confronted Entreri near the entrance of Mithral Hall. Jierdan proved to be an equal match during the beginning of the fight, although he noted that he would tire long before Entreri. Jierdan attempted to use the unconscious Sydney as an excuse to halt his fight with Entreri, and was promptly killed by Entreri's vampiric dagger.