Hedrun was born into the Tribe of the Elk as the daughter of Soren Arnsfirth. At a young age, she was promised to Olaf Tormhaalt, son of the tribe's shaman. However, when her Chosen powers first manifested, Hedrun accidentally killed Olaf and was banished from the tribe. Her powers permitted her to survive in the winter and, in her fury and desire for vengeance, Hedrun gladly embraced the will of Auril.
She started gathering an army of animals and monsters. Soon, even the Tribe of the Bear pledged themselves to the Ice Witch. They started to construct a temple to Auril in the old lair of Ingeloakastimizilian. Hedrun then started a war in Icewind Dale with her troops attacking all of its communities. The Ten Towns defended themselves but in response, she sent an army to attack Bryn Shander. In the meantime, she sent her captured father as her envoy to the Elk Tribe demanding their submission. In the end, however, an adventuring party defeated her.
Hedrun survived the war, though it was unclear how—either through simulacrum magic or undeath as a wight—only to be captured by the Red Wizards of Thay, who transported her to Doomvault for experimentation.